Kidney function, medication dosing, UV exposure, and health screening calculators. Browse our free general health tools below — all calculators are instant, accurate, and require no sign-up.
20/20 Vision Calculator — Convert Snellen visual acuity to LogMAR, decimal, and MAR. Check driving eligibility and compare vision classification across international standards.
6-Minute Walk Test Calculator — Calculate 6MWT predicted distance using Enright equations. Evaluate percent predicted, NYHA class, oxygen desaturation, chronotropic index, and DSP.
A-a Gradient Calculator — Calculate the alveolar-arterial oxygen gradient from ABG values. Includes P/F ratio, expected gradient by age, altitude adjustment, and differential diagnosis table.
Ankle-Brachial Index Calculator — Calculate the ankle-brachial index (ABI) for PAD screening. Interprets severity, flags non-compressible arteries, inter-arm differences, and Rutherford classification.
ACFT Score Calculator — Legacy Army Combat Fitness Test (ACFT) score calculator for archived six-event scores and historical reference use.
Acid-Base Disorder Calculator — Interpret ABG results with step-by-step acid-base analysis. Calculates anion gap, delta-delta ratio, Winter's formula, and identifies primary and mixed disorders.
Albumin-to-Creatinine Ratio Calculator — Calculate urine albumin-to-creatinine ratio (ACR) with KDIGO staging. Classifies microalbuminuria, macroalbuminuria, and CKD prognosis by GFR and albuminuria.
Addiction Screening Calculator — CAGE and DAST-10 substance use screening questionnaires. Scores, interprets severity, and provides recommended actions for alcohol and drug use assessment.
Adrenal CT Washout Calculator — Calculate absolute and relative percentage washout for adrenal masses. Differentiates adenoma from metastasis/carcinoma with contrast enhancement curves.
AHI (Apnea-Hypopnea Index) Calculator — Calculate your Apnea-Hypopnea Index from sleep study data. Includes supine AHI, REM AHI, positional analysis, and severity grading.
Ankle Fracture Treatment Calculator — Ottawa ankle rules, Weber classification, and stability assessment for ankle fractures. Evaluates medial clear space, syndesmosis, talar tilt, and treatment decisions.
Air Force PT Test Score Calculator — Legacy/pre-transition USAF Physical Fitness Assessment score calculator for the older composite PT model before the 2026 PFRA rollout.
Alcohol BAC Estimator Calculator — Estimate your Blood Alcohol Concentration (BAC) using the Widmark formula. See how long until your BAC returns to zero and understand impairment levels.
Alcohol Units Calculator — Convert drinks to UK units, US standard drinks, and Australian standard drinks. Calculates alcohol grams, calories, estimated BAC, and weekly risk assessment.
Alzheimer's Stage And Care Context Worksheet — Review broad Alzheimer's stage and support context from MMSE, diagnosis stage, comorbidities, mobility, and nutrition in a conservative educational worksheet.
ANC (Absolute Neutrophil Count) Calculator — Calculate your absolute neutrophil count from CBC with differential. Includes ALC, AMC, AEC, severity grading, febrile neutropenia risk, and causes of neutropenia.
ANC Calculator (Without Bands) — Calculate absolute neutrophil count when bands are not reported. Includes NLR (neutrophil-to-lymphocyte ratio), all absolute counts, severity grading, and percentage or absolute input modes.
Anion Gap Calculator — Calculate serum anion gap and albumin-corrected anion gap. Differentiate metabolic acidosis causes with clinical interpretation.
APFT (Army Physical Fitness Test) Score Calculator — Calculate your APFT score with push-ups, sit-ups, and 2-mile run. Age and gender-adjusted scoring with minimum standards, promotion points, and fitness category.
Arterial (Vascular) Age Calculator — Estimate your arterial age based on cardiovascular risk factors. Compare vascular age to chronological age with modifiable risk reduction recommendations.
AST:ALT Ratio (De Ritis Ratio) Calculator — Calculate the AST to ALT ratio (De Ritis ratio) and R factor to review common liver-injury patterns alongside the rest of the liver panel.
AUDIT-C Alcohol Screening Calculator — Calculate your AUDIT-C score for alcohol use screening. 3-question validated tool with sex-specific thresholds, sensitivity data, and clinical intervention recommendations.
AUDIT-10 (Full AUDIT) Alcohol Assessment Calculator — Complete AUDIT-10 alcohol use disorder screening tool. All 10 WHO questions with zone scoring, 3-domain breakdown, AUD severity estimation, and evidence-based intervention guide.
Baby Eye Color Predictor Calculator — Predict your baby's eye color probability from parent and grandparent eye colors. Simplified Mendelian genetics model with probability bars, color charts, and eye color facts.
Baby's Milk Intake Calculator — Calculate recommended daily and per-feed milk intake for babies 0-12 months by weight and age. Covers formula and breast milk with growth spurt timing and feeding guidelines.
BAC (Blood Alcohol Content) Calculator — Estimate your blood alcohol content using the Widmark formula. Factors in sex, weight, drinks, time, and stomach contents with impairment levels and legal limits worldwide.
Back to Normal Life (Surgery Recovery) Calculator — Estimate your personalized surgery recovery timeline adjusted for age, fitness, BMI, smoking, diabetes, and complications. Activity milestones for desk work, driving, exercise, and full recovery.
BAI (Body Adiposity Index) Calculator — Calculate your Body Adiposity Index from hip circumference and height. Estimates body fat percentage without a scale, with sex-specific categories and comparison to BMI.
BBT (Basal Body Temperature) Calculator — Track your basal body temperature for fertility awareness. Estimates ovulation day, cycle phase, fertility window, thermal shift detection with the 3-over-6 rule, and cycle timeline visualization.
Bed Size Calculator — Find the right bed size for your room, height, and number of sleepers. Calculates per-person width, height clearance, room coverage, walking space, and sheet sizes.
BEE / BMR (Basal Energy Expenditure) Calculator — Calculate your Basal Metabolic Rate using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas. Estimates TDEE, macro targets, and weight management calorie levels.
Benzodiazepine Conversion & Equivalence Calculator — Convert between benzodiazepine doses using diazepam equivalents. Includes a 12-drug equivalence table, half-life context, and general taper-reference notes.
Berg Balance Scale (BBS) Calculator — Score the 14-item Berg Balance Scale for fall risk assessment in older adults. Visual breakdown per task, fall risk thresholds, and minimal clinically important difference guidance.
BIMS (Brief Interview for Mental Status) Calculator — Score the BIMS cognitive screening from the MDS 3.0. Tests repetition, temporal orientation, and recall with interpretation thresholds for intact, moderate, and severe impairment.
Bladder Volume Calculator — Estimate urinary bladder volume from ultrasound dimensions using the ellipsoid formula. Includes post-void residual interpretation, age-based capacity norms, and measurement method comparison.
BMI Amputee Calculator — Calculate adjusted BMI for amputees using body-weight correction factors. Accurate BMI estimation accounting for limb loss with standard amputation percentages.
Breast Cancer Recurrence Risk Worksheet — Review broad breast-cancer recurrence-context bands from tumor size, grade, nodal status, and receptor pattern in a simplified educational worksheet.
Breast Cancer Risk Calculator (Gail Model) — Estimate 5-year and lifetime breast cancer risk using Gail Model factors: age, menarche, first birth, family history, biopsies, and atypical hyperplasia. Includes chemoprevention and screening guid...
Body Roundness Index (BRI) Calculator — Calculate the Body Roundness Index from waist circumference and height. Compares BRI to BMI, WHtR, and ABSI with cardiometabolic risk categories and waist circumference thresholds.
Caffeine Calculator — Calculate total caffeine intake from multiple sources, track metabolic decay with half-life modeling, check daily limits, and estimate time until sleep-safe levels. 20+ drink database included.
Caffeine Half-Life Calculator — Calculate how much caffeine remains in your body over time. See hourly caffeine decay, find your ideal cutoff time before bed, and understand caffeine metabolism.
CAGE Questionnaire Calculator — Score the 4-question CAGE alcohol screening questionnaire. Includes interpretation thresholds, SBIRT workflow, and comparison to AUDIT, AUDIT-C, MAST, and other screening tools.
Charlson Comorbidity Index (CCI) Calculator — Calculate the Charlson Comorbidity Index with age adjustment from 19 comorbid conditions. Includes survival estimates, condition weights, and organ system breakdown.
Car Heat Calculator — Estimate interior car temperature based on outside temperature, sun exposure, window status, and vehicle color. Includes temperature timeline, heatstroke warning signs, and safety guidance.
Crohn's Disease Activity Index (CDAI) Calculator — Calculate the CDAI score from 8 weighted clinical variables. Includes component breakdown, activity classification, and common clinical-trial thresholds.
Cigarette Cost & Health Impact Calculator — Estimate the financial cost and public-health impact of smoking. Includes pack-years, savings projections, and a quit-smoking recovery timeline.
Circadian Rhythm Sleep Phase Calculator — Estimate a circadian-style sleep schedule from wake time, sleep goal, and chronotype. Includes bedtime, caffeine cutoff, and daily timing reference windows.
CIWA-Ar Alcohol Withdrawal Assessment Calculator — Calculate the CIWA-Ar score (Clinical Institute Withdrawal Assessment for Alcohol) to assess alcohol-withdrawal severity and place the result in pathway context.
Corrected Calcium Calculator — Calculate albumin-corrected calcium from measured serum calcium and albumin levels. Detect true hypocalcemia or hypercalcemia in hypoalbuminemic patients.
COVID-19 Event Risk Worksheet — Estimate the chance that at least one attendee is infectious and compare broad mitigation scenarios with a simplified COVID event-risk worksheet.
Corrected Magnesium Calculator — Calculate an albumin-adjusted magnesium estimate and review broad magnesium context with a cautious educational worksheet.
COVID-19 Severity Context Calculator — Review age- and comorbidity-based COVID severity context with a simplified educational model for infection fatality, hospitalization, ICU, and long-COVID bands.
Colorectal Cancer Screening Risk Calculator — Review colorectal cancer screening context from age, family history, and common risk factors. Compares your profile with common screening pathways and discussion points.
Creatinine Clearance Calculator (Cockcroft-Gault) — Calculate creatinine clearance using the Cockcroft-Gault equation with actual, ideal, and adjusted body weight. Review the result in renal-function and medication-dosing context.
Creatinine Clearance Calculator — Calculate creatinine clearance using the Cockcroft-Gault equation. Estimate kidney function for drug dosing and renal assessment.
CURB-65 Pneumonia Severity Score Calculator — Calculate the CURB-65 score for community-acquired pneumonia severity assessment and see 30-day mortality plus published care-setting context.
Crown-Rump Length Gestational Age Calculator — Calculate gestational age and estimated due date from crown-rump length (CRL) ultrasound measurement using Robinson or Hadlock formulas.
Dual Antiplatelet Therapy Duration Calculator — Review DAPT-duration context after coronary stenting using published bleeding and ischemic risk factors. DAPT score with stent type and OAC considerations.
Cardiovascular Disease 10-Year Risk Calculator — Estimate your 10-year cardiovascular risk with a Pooled Cohort Equations-style worksheet and use the result as a primary-prevention discussion aid.
Denver HIV Risk Score Calculator — Estimate how behavioral and demographic factors fit into the Denver HIV Risk Score and use the result as an HIV screening and prevention discussion aid.
PHQ-9 Depression Screening Questionnaire Calculator — Screen for depression using the PHQ-9 questionnaire. Score severity, get treatment recommendations, and track symptoms over time with this validated tool.
Maddrey Discriminant Function Calculator — Calculate the Maddrey Discriminant Function (MDF) for alcoholic-hepatitis severity context and compare it with related liver-severity markers such as MELD.
DLBCL IPI Prognosis Calculator — Review the International Prognostic Index (IPI) and related prognostic context for diffuse large B-cell lymphoma.
Dietary Reference Intake (DRI) Calculator — Calculate your daily Dietary Reference Intakes (DRI) for vitamins, minerals, and macronutrients. Personalized RDA values based on age, sex, and activity.
Archery Draw Length Calculator — Calculate your archery draw length from wingspan, height, or forearm measurements. Get arrow length, spine recommendations, and bow size guidance.
Due Date Calculator — Calculate your estimated due date (EDD) using Naegele's rule from your last menstrual period, conception date, or IVF transfer date. View trimester timeline and key milestones.
Estimated Due Date (EDD) Calculator — Calculate your estimated due date using LMP, ultrasound dating, or known conception date. Includes pregnancy timeline, gestational age, and term classifications.
eGFR Calculator — Calculate estimated glomerular filtration rate using the CKD-EPI 2021 race-free equation. Determine chronic kidney disease stage and kidney function.
Estimated Energy Requirement (EER) Calculator — Calculate your daily Estimated Energy Requirement using the IOM equation. Compare BMR methods, get AMDR macronutrient ranges, and plan for weight goals.
Effective Regurgitant Orifice Area (EROA) Calculator — Calculate EROA via PISA or volumetric method for mitral and aortic regurgitation severity grading. Includes regurgitant volume, fraction, and ASE severity tables.
Endotracheal Tube (ETT) Size Calculator — Estimate endotracheal tube size for pediatric and adult patients using age-based formulas, size tables, insertion depth, suction catheter, and blade references.
Exclusive Pumping Schedule & Volume Calculator — Calculate daily breast milk needs, pumping schedules, and supply tracking for exclusively pumping mothers. Includes storage guidelines and age-based schedules.
Face Shape Calculator — Determine your face shape from measurements. Get personalized eyewear, hairstyle, and makeup recommendations for oval, round, square, heart, diamond, oblong, and triangle face shapes.
Fagerström Test for Nicotine Dependence (FTND) Calculator — Assess nicotine dependence severity with the 6-item Fagerström Test. Get FTND score, dependence level, pharmacotherapy recommendations, and cessation treatment guidance.
Fractional Excretion of Sodium (FENa) Calculator — Calculate FENa to differentiate prerenal from intrinsic renal AKI. Includes FENa formula, AKI diagnostic indices comparison, and clinical interpretation with diuretic use guidance.
Fertility by Age Calculator — Estimate natural and IVF pregnancy rates by age. Includes cumulative probability, miscarriage and aneuploidy risk, AMH interpretation, and time-to-conceive milestones.
Fractional Excretion of Urea (FEUrea) Calculator — Calculate FEUrea to differentiate prerenal from intrinsic AKI in patients on diuretics. Includes FEUrea vs FENa comparison, AKI diagnostic indices, and clinical interpretation.
FIB-4 Index Calculator — Hepatic Fibrosis — Calculate the FIB-4 index for liver fibrosis risk screening using age, AST, ALT, and platelets, with age-adjusted cutoffs and APRI comparison.
Fish Oil / Omega-3 Dosage Calculator — Calculate daily EPA and DHA omega-3 requirements by health condition. Includes dietary fish intake, supplement dosing, cost estimates, and fish omega-3 content reference table.
Finnegan Neonatal Abstinence Score Worksheet — Calculate the Finnegan NAS to review neonatal opioid withdrawal severity, repeated-score thresholds, and category breakdowns in worksheet form.
Free Testosterone Calculator (Vermeulen Method) — Calculate free and bioavailable testosterone using total testosterone, SHBG, and albumin. Includes age-adjusted references, SHBG interpretation, testosterone fractions visualization.
Breast Pump Flange Size Calculator — Find your correct breast pump flange size based on nipple diameter and elasticity. Includes brand availability, fit assessment, size reference table, and signs of poor fit.
Glasgow Coma Scale (GCS) Calculator — Calculate the Glasgow Coma Scale score from eye, verbal, and motor responses. Includes GCS-Pupils score, severity classification, airway decision support, mortality estimates, and motor score analy...
GAD-7 Anxiety Screening Calculator — Score the GAD-7 generalized anxiety disorder questionnaire. Includes severity interpretation, item-level analysis, and symptom-domain context.
Glucose Infusion Rate (GIR) Calculator — Calculate glucose infusion rate from dextrose concentration, IV rate, and weight. Includes neonatal/pediatric/adult targets, reverse calculation, dextrose concentration table, and hypoglycemia prot...
Glycemic Index & Glycemic Load Calculator — Calculate glycemic index and glycemic load for foods and meals. Includes 29-food reference database, meal GI calculator, GL classification, and blood sugar impact estimates.
Gorlin Formula Valve Area Calculator — Calculate cardiac valve area using the Gorlin formula from catheterization data including cardiac output, heart rate, and pressure gradient.
Glomerular Filtration Rate (GFR) Calculator — Estimate kidney filtration using CKD-EPI 2021, MDRD, Cockcroft-Gault, and cystatin C equations. Includes CKD staging context, albuminuria categories, and equation comparison for medication-review or referral discussions.
GRACE ACS Risk Score Calculator — Calculate the GRACE score for acute coronary syndrome risk stratification including in-hospital and 6-month mortality prediction.
Gout Diagnosis Scoring Calculator — Score gout probability using the ACR/EULAR 2015 classification criteria with serum urate levels, joint involvement, and imaging findings.
Growth Chart Percentile Calculator — Calculate height-for-age and weight-for-age percentiles for children 2-20 using CDC growth reference data. Track growth patterns and identify potential concerns.
Hand Sanitizer Effectiveness Calculator — Estimate hand sanitizer efficacy based on type, alcohol concentration, application time, volume, and hand condition with pathogen comparison.
hCG Levels and Doubling Time Tracker — Track serial hCG levels, calculate doubling time, and compare the most recent value with gestational-age reference ranges for early-pregnancy trend context.
Subjective Happiness Scale Calculator — Assess subjective happiness using the validated 4-item SHS by Lyubomirsky & Lepper with normative comparisons and well-being factor analysis.
Hematocrit to Hemoglobin Ratio Converter — Convert between hematocrit and hemoglobin values with reference-range context, screening-level anemia bands, and a simple altitude adjustment note.
Hearing Loss Frequency Calculator — Calculate Pure Tone Average (PTA) from audiogram frequencies and classify hearing loss severity using WHO criteria. Enter dB HL values for each frequency.
HOMA-IR Insulin Resistance Calculator — Calculate HOMA-IR, HOMA-B beta cell function, and QUICKI index from fasting insulin and glucose to assess insulin resistance severity.
Heat Index Health Risk Calculator — Calculate the heat index (feels-like temperature) from air temperature and humidity. Get NWS health risk classification and outdoor activity safety guidelines.
ICH Score Prognosis Worksheet — Calculate the Intracerebral Hemorrhage (ICH) score and review the historical 30-day and 12-month mortality context alongside the score breakdown.
Hepatic Steatosis Index Calculator — Calculate the Hepatic Steatosis Index (HSI) to screen for non-alcoholic fatty liver disease using ALT, AST, BMI, diabetes status, and sex.
Implantation Calculator — Estimate your likely implantation window and testing timeline based on ovulation, LMP, or IVF transfer date, using a DPO 6-12 reference chart.
ICH Volume Calculator (ABC/2 Method) — Estimate intracerebral hemorrhage volume using the ABC/2 method from CT imaging and place the result in common ICH scoring and literature reference ranges.
Isotretinoin (Accutane) Dose Calculator — Calculate isotretinoin cumulative dose, track treatment progress, and review lab values. Includes dosing by severity, iPLEDGE reminders, and lab schedules.
Incidence Rate Calculator — Calculate disease incidence rates per 1,000 or 100,000 person-time with confidence intervals. Compare periods and convert between epidemiologic measures.
IV Drip Rate Calculator — Calculate IV drip rate in drops per minute (gtts/min) and mL per hour from volume, time, and drop factor as a reference worksheet.
Injury Severity Score (ISS) Calculator — Calculate the Injury Severity Score from AIS ratings across 6 body regions. Includes NISS plus simplified RTS/TRISS context and mortality ranges.
Karvonen Formula Calculator — Calculate target heart rate zones using the Karvonen (Heart Rate Reserve) method. Compare 5 training zones with resting HR-adjusted targets for personalized exercise.
Kidney Failure Risk Equation (KFRE) Calculator — Estimate 2-year and 5-year risk of treated kidney failure with a 4-variable KFRE worksheet. Includes CKD stage, albuminuria category, and the KDIGO heatmap for review context.
Kt/V Calculator (Dialysis Adequacy) — Calculate Kt/V dialysis adequacy using the Daugirdas II formula. Includes spKt/V, eKt/V, URR, stdKt/V, Watson body water, and adequacy troubleshooting.
Kidney Stone Calculator — Estimate spontaneous passage rates by stone size and location, treatment options, prevention strategies, and 24-hour urine interpretation for kidney stones.
Luteal Phase Calculator — Calculate luteal phase length from cycle data, estimate implantation timing windows, and review progesterone values in general cycle-tracking context.
Local Anesthetic Dosing Calculator — Estimate local anesthetic maximum dose and volume by agent, concentration, weight, and epinephrine use.
Mask vs. No Mask Calculator — Compare respiratory infection transmission models with and without masking. Explore different mask types, compliance levels, and population-level impact.
Lymphocyte Count & WBC Differential Calculator — Calculate absolute lymphocyte count (ALC), ANC, NLR, and the full WBC differential from CBC results as a structured interpretation worksheet.
MCA-PSV Doppler Calculator (Fetal Anemia) — Convert MCA peak systolic velocity to multiples of median (MoM) using Mari reference values and review the result in fetal-anemia screening context.
Mcg to IU Converter (Vitamins) — Convert between micrograms (mcg) and International Units (IU) for Vitamin D, A, and E with RDA comparison and safety assessment.
Mean Sac Diameter Calculator (Early Pregnancy) — Calculate mean gestational sac diameter, estimate gestational age, and review early-pregnancy ultrasound findings against conservative SOM and ACOG reference thresholds.
Mean Airway Pressure & Oxygenation Index Calculator — Calculate mean airway pressure (MAP), oxygenation index (OI), P/F ratio, and driving pressure for conventional and HFOV ventilation with severity grading.
Medical Radiation Dose Calculator — Calculate radiation dose from X-rays, CT scans, and nuclear medicine in mSv with background equivalents, cancer risk estimates, and fetal dose assessment.
Medical Unit Converter Calculator — Convert common lab values between conventional (US) and SI (international) units. Covers glucose, cholesterol, hemoglobin, creatinine, and 20+ lab tests.
Menstrual Cycle Tracker Calculator — Track your menstrual cycle phases — follicular, ovulatory, and luteal. Predict next period date, PMS window, and cycle regularity from your average cycle length.
Medication Dose by Weight Calculator — Calculate weight-based medication doses for common OTC medications. Get dose per kg calculations for acetaminophen, ibuprofen, and other non-prescription drugs.
Kidney Transplant Graft-Survival Worksheet — Review kidney transplant graft-survival context from donor age, HLA mismatch, cold ischemia time, PRA, donor type, and retransplant status in a simplified educational worksheet.
Metastatic Prostate Cancer Prognosis Worksheet — Review broad metastatic prostate-cancer prognostic context from disease setting, metastatic burden, PSA, grade group, performance status, and key labs in a simplified educational worksheet.
MME Calculator — Morphine Milligram Equivalents — Calculate total daily morphine milligram equivalents (MME) from multiple opioids with CDC reference bands, equianalgesic conversion context, and naloxone review cues.
MIPI Score Calculator — Mantle Cell Lymphoma — Calculate the Mantle Cell Lymphoma International Prognostic Index (MIPI and MIPI-c) for risk stratification and prognosis context in mantle cell lymphoma.
Mortality Rate Calculator — Calculate crude, cause-specific, case fatality, infant, neonatal, maternal mortality rates, PMR, and YPLL with interpretation and global benchmarks.
mmol/L to mg/dL Converter — Convert lab values between mmol/L and mg/dL for glucose, cholesterol, creatinine, calcium, and 14 common analytes with reference ranges and batch mode.
NEDOCS Calculator — Calculate the National Emergency Department Overcrowding Score to objectively assess ED crowding level and benchmark operational strain.
Navy PRT Calculator — Calculate Navy Physical Readiness Test scores for push-ups, plank, 1.5-mile run, and body composition assessment with age/sex-specific standards.
Neutrophil-to-Lymphocyte Ratio (NLR) Calculator — Calculate NLR from CBC results with context-specific reference thresholds across general, infectious, cardiovascular, and oncology settings. Includes PLR, LMR, and SII.
NIH Stroke Scale (NIHSS) Calculator — Calculate the NIH Stroke Scale score to quantify stroke severity, summarize the exam, and place the result in stroke-pathway context with all 15 examination items.
Noise Pollution & Hearing Risk Calculator — Calculate noise exposure dose, safe duration limits, and hearing damage risk with OSHA/NIOSH standards, dB combination, distance correction, and protection effectiveness.
Number Needed to Treat (NNT) Calculator — Calculate NNT, NNH, ARR, RRR, relative risk, and odds ratio from clinical trial data with confidence intervals and cost-effectiveness analysis.
Opioid Withdrawal (COWS) Worksheet — Score opioid withdrawal severity using the Clinical Opiate Withdrawal Scale (COWS) with timing context for withdrawal review and MOUD discussions.
Nuchal Translucency (NT) Screening Calculator — Estimate first-trimester trisomy screening context from NT measurement and maternal age, with optional nasal-bone context. This page is educational and does not reproduce a full combined-screening report.
Ovulation Calculator — Calculate your ovulation day and fertile window based on your last menstrual period and cycle length. Identify up to 6 fertile days each month for conception planning.
Osmolality Gap Calculator — Calculate serum osmolality and the osmolal gap from common chemistry inputs. Use it as an interpretation aid when reviewing unmeasured osmoles alongside the broader clinical picture.
Pack-Years Calculator — Calculate pack-year smoking history and place it in smoking-exposure, screening, and risk-context reference ranges.
Parkland Formula (Burn Resuscitation) Calculator — Calculate an initial burn-fluid worksheet using the Parkland formula with Rule of Nines TBSA estimation, delayed presentation adjustment, and pediatric context.
Pediatric BMI Percentile Calculator — Calculate BMI-for-age percentile for children ages 2-20. Classify weight status using CDC growth chart categories: underweight, normal, overweight, and obese.
PECARN Pediatric Head Injury Calculator — Use the PECARN pediatric head-injury rule as an educational worksheet for minor blunt head trauma and to frame observation-versus-imaging reference context.
Period & Menstrual Cycle Calculator — Track your menstrual cycle, predict next period and ovulation dates, identify fertile windows, and understand cycle phases with this free period calculator.
Plasma Volume Calculator — Estimate total blood volume, plasma volume, and red cell volume using Nadler, Lemmens, or Gilcher methods. Calculate allowable blood loss for surgical planning.
Pregnancy Weight Gain Calculator — Review pregnancy weight-gain reference ranges based on IOM 2009 guidance and pre-pregnancy BMI. Includes trimester context for singleton and twin pregnancies.
Pneumonia Severity Index (PSI/PORT) Calculator — Calculate the PSI/PORT score to assess pneumonia severity and 30-day mortality risk class. Useful for site-of-care review in community-acquired pneumonia.
Prescription Refill Date Calculator — Calculate when to refill your prescription based on pill count, dosing frequency, and lead time. Plan ahead to never run out of medication.
Qp/Qs Ratio Calculator — Pulmonary-to-Systemic Flow — Calculate the Qp/Qs ratio from cardiac-catheterization oxygen saturations to review intracardiac shunt magnitude in ASD, VSD, PDA, and related congenital-heart contexts.
Post-Void Residual Volume (PVR) Calculator — Calculate and interpret post-void residual urine volume, voiding efficiency, and flow rate as a lower-urinary-tract worksheet rather than a stand-alone treatment rule.
Quarantine Activity & Indoor Exercise Planner — Plan effective indoor workouts during quarantine or home isolation. Calculate calories burned for bodyweight exercises, yoga, HIIT, and more based on your space and fitness level.
QTc Calculator — Corrected QT Interval — Calculate corrected QT interval using Bazett, Fridericia, Framingham, and Hodges formulas. Assess risk for QT prolongation and Torsades de Pointes.
Rate Pressure Product (RPP) Calculator — Calculate Rate Pressure Product to estimate myocardial workload, with MAP, pulse pressure, and common symptom-threshold context rather than a stand-alone exercise prescription.
QUICKI Insulin Sensitivity Calculator — Calculate QUICKI, HOMA-IR, HOMA-beta, and related fasting metabolic indexes from fasting insulin and glucose as a screening worksheet for insulin-sensitivity context.
REM Sleep & Sleep Cycle Calculator — Estimate your REM sleep, deep sleep, and sleep cycle distribution based on total sleep time, age, and sleep quality factors. Includes cycle-by-cycle breakdown and optimization tips.
RCRI — Revised Cardiac Risk Index Calculator — Calculate RCRI (Lee Index) for perioperative cardiac risk stratification. Estimates major adverse cardiac event probability before non-cardiac surgery using 6 clinical predictors.
RMR — Resting Metabolic Rate Calculator — Calculate your resting metabolic rate using Mifflin-St Jeor, Harris-Benedict, Katch-McArdle, and Cunningham formulas. Get TDEE, calorie targets, and macronutrient estimates.
Type 2 Diabetes Risk Calculator (FINDRISC) — Use a FINDRISC-style worksheet to organize common type 2 diabetes risk factors, screening context, and modifiable lifestyle factors in one place.
SAAG — Serum-Ascites Albumin Gradient Calculator — Calculate the Serum-Ascites Albumin Gradient to differentiate portal-hypertensive from non-portal ascites. Includes ANC screening context, LDH analysis, and a reference pattern table.
RSBI — Rapid Shallow Breathing Index Calculator — Calculate the Rapid Shallow Breathing Index (f/VT) as a spontaneous-breathing worksheet, with P/F ratio and checklist context rather than a stand-alone extubation order.
SCORAD — Atopic Dermatitis Severity Calculator — Calculate the Scoring Atopic Dermatitis (SCORAD) index to review eczema extent, intensity, and symptom burden in one severity worksheet.
SAPS II — Simplified Acute Physiology Score Calculator — Calculate the SAPS II ICU severity score from 17 variables. Estimates hospital mortality risk for critically ill patients using the worst values in the first 24 hours of ICU admission.
Sobriety & BAC Calculator — Blood Alcohol Estimator — Estimate your current blood alcohol concentration (BAC), time to sober, and impairment level using the Widmark formula. Includes hourly BAC timeline and effects reference.
Sleep Time Calculator — Bedtime & Wake Cycle Planner — Calculate the ideal bedtime based on your wake-up time, sleep cycles, and age. Aligns with 90-minute cycles and National Sleep Foundation recommendations.
Semen Analysis Calculator — WHO 2021 Reference Values — Interpret semen analysis results against WHO 2021 (6th edition) reference limits. Calculates total motile count, functional sperm, and ART suitability assessment.
Social Distancing & Exposure Risk Calculator — Estimate respiratory illness transmission risk based on distance, duration, masks, ventilation, vaccination status, and community prevalence. Includes mitigation checklist.
Standard Drink Calculator — Alcohol Content Converter — Convert any alcoholic beverage to standard drinks (US, UK, AU, CA). Calculate pure alcohol grams, calories, metabolism time, and compare 15+ common drink types.
Corticosteroid Conversion Calculator — Steroid Equivalency — Convert between corticosteroids using equipotent anti-inflammatory dose equivalency. Compares 8 steroids with relative potency, mineralocorticoid activity, half-life, and exposure context.
STOP-BANG Score — OSA Screening Calculator — Screen for obstructive sleep apnea risk using the STOP-BANG questionnaire. 8 yes/no questions with risk stratification and predictive performance data.
Testosterone to Estradiol Ratio (T:E2) Calculator — Calculate the testosterone-to-estradiol ratio with male reference ranges, assay notes, and hormone-balance context rather than medication instructions.
TTKG Calculator — Transtubular Potassium Gradient — Calculate the transtubular potassium gradient (TTKG) as a renal-potassium-handling worksheet for hyperkalemia or hypokalemia review, with validity checks and limitation notes.
Urine Output Calculator — mL/kg/hr & AKI Staging — Calculate urine output rate (mL/kg/hr), classify oliguria/anuria/polyuria, and assess KDIGO AKI staging by urine output. Supports adults, children, infants, and neonates with hourly tracking.
Twinning Rate Calculator — Twin Pregnancy Probability — Estimate a worksheet-style twinning risk based on maternal age, population context, family history, parity, BMI, prior twins, and IVF/embryo transfer count. Includes DZ/MZ breakdown and ethnic comparison.
URR & Kt/V Calculator — Dialysis Adequacy — Calculate urea reduction ratio (URR) and Kt/V (Daugirdas) for hemodialysis adequacy assessment. Includes eKt/V, UF rate monitoring, KDOQI reference bands, and common low-clearance review areas.
UV Exposure Time Calculator — Calculate safe sun exposure time based on UV index, skin type (Fitzpatrick I–VI), and SPF. Get sunscreen reapplication schedules and UV protection guidelines.
Vision Prescription Converter Calculator — Convert between vision prescription formats including diopters, Snellen, and LogMAR. Plus glasses-to-contacts conversion with vertex distance correction.
SIR Model Epidemic Simulator — Viral Infection Spread — Simulate viral epidemic spread using the SIR (Susceptible-Infected-Recovered) compartmental model. Set R₀, vaccination, interventions, and view epidemic curves, peak timing, attack rates, and herd...
Wake-Up Time & Sleep Cycle Calculator — Find ideal bedtimes or wake-up times aligned to 90-minute sleep cycles. Includes sleep stage visualization, NSF age-specific recommendations, and sleep hygiene tips.
Warsaw Method — Neonatal Fluid Calculator — Compare neonatal fluid-reference ranges using the Warsaw graduated fluid approach. Supports ELBW, VLBW, and term infants with insensible-loss adjustments for worksheet-style comparison.
Wind Chill Health Risk Calculator — Calculate wind chill temperature from air temperature and wind speed. Get NWS frostbite risk times and cold weather safety guidelines for outdoor activity.