eGFR Calculator
Calculate estimated glomerular filtration rate using the CKD-EPI race-free creatinine equation. Review chronic kidney disease stage bands and kidney-function context.
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.
⚠️ Worksheet Note: KFRE is a risk-framing tool for treated kidney failure, not a referral or treatment protocol. This page is best used to add context to CKD stage, albuminuria, and lab trends rather than to generate a care plan by itself.
Additional Labs (optional)
These labs are used only for contextual flags below and do not change the 4-variable KFRE score on this page.
2-Year Risk of Kidney Failure⧉
3.8%
Estimated probability of treated kidney failure within 2 years under the 4-variable KFRE implementation used on this page.
5-Year Risk of Kidney Failure⧉
13.9%
Estimated 5-year probability from the same worksheet model. Health systems sometimes map risk ranges to review intensity, but this page does not assign a care pathway.
CKD Stage⧉
G3b (Moderate-severe) (eGFR 35)
KDIGO 2012 classification based on eGFR.
Albuminuria Category⧉
A3 (Severely increased)
A1: <30 mg/g, A2: 30-300 mg/g, A3: >300 mg/g. Higher albuminuria independently predicts faster progression.
Review Context⧉
Higher-risk CKD profile that often leads to closer kidney-focused review
A worksheet summary based on the current eGFR, albuminuria pattern, and KFRE range. It is intended for review context, not referral instructions.
Threshold Context⧉
Elevated 5-year risk range that can prompt closer review of trajectory
Shows how the current risk sits relative to higher-risk KFRE ranges sometimes cited in CKD programs. It is not a dialysis or transplant planning protocol.
KDIGO Risk Heatmap (CKD Prognosis)
| GFR Stage | A1 (<30 mg/g) | A2 (30-300) | A3 (>300) |
|---|---|---|---|
| G1 (≥90) | Low | Mod | High |
| G2 (60-89) | Low | Mod | High |
| G3a (45-59) | Mod | High | Very High |
| G3b (30-44) | High | Very High | Very High |
| G4 (15-29) | Very High | Very High | Very High |
| G5 (<15) | Very High | Very High | Very High |
Planning notes, formulas, and examples
About the Kidney Failure Risk Equation (KFRE) Calculator
The Kidney Failure Risk Equation (KFRE) estimates the risk of treated kidney failure over 2 and 5 years for people with chronic kidney disease. The 4-variable model uses age, sex, eGFR, and urine albumin-to-creatinine ratio (ACR) to frame progression risk rather than relying only on the baseline eGFR value entered on the page.
That makes the page useful as a worksheet for comparing patients who may share a similar CKD stage but have very different albuminuria patterns and long-term risk. The KDIGO stage and heatmap are shown alongside the KFRE result so the estimate can be read in broader CKD context.
This page is designed for risk framing and review context. It does not generate referral instructions, dialysis plans, or treatment orders, and the optional lab inputs below are used only for contextual lab flags rather than the KFRE calculation itself.
When This Page Helps
KFRE is useful because it adds a progression estimate to CKD stage and albuminuria rather than relying only on a single kidney-function cutoff. That helps explain why two patients with similar eGFR can have very different risk profiles over time.
How to Use the Inputs
- Enter age and sex
- Enter the eGFR value you want to evaluate
- Enter urine albumin-to-creatinine ratio (ACR) in mg/g or mg/mmol
- Optionally enter calcium, phosphate, albumin, and bicarbonate for contextual lab flags; these do not change the KFRE score on this page
- Review the 2-year and 5-year KFRE estimate alongside CKD stage, albuminuria category, and the KDIGO heatmap
- Use the review-context text as a framing aid rather than a referral or treatment pathway
Formula used
KFRE 4-variable implementation on this page: Risk = 1 − S0^exp(LP), where LP = −0.2201 × (age/10 − 7.036) + 0.2467 × (male − 0.5642) − 0.5567 × (eGFR/5 − 7.222) + 0.4510 × (ln ACR − 5.137). This page uses baseline survival values of 0.9832 at 2 years and 0.9365 at 5 years. CKD Stage: G1 (≥90), G2 (60-89), G3a (45-59), G3b (30-44), G4 (15-29), G5 (<15).Example Calculation
Result: 2-year risk: 3.8%, 5-year risk: 13.9% — higher-risk review context
A 55-year-old male with eGFR 35 and ACR 300 falls in CKD G3b/A3 and remains in a high-risk KDIGO heatmap cell. With the fixed 4-variable KFRE implementation used on this page, the estimate is about 3.8% at 2 years and 13.9% at 5 years. That is best read as a higher-risk CKD worksheet pattern rather than a stand-alone referral or kidney-replacement plan.
Tips & Best Practices
- Use a stable outpatient eGFR and urine ACR when possible, because unstable values can distort the risk estimate.
- ACR contributes strongly to the score, so unit conversion and sample timing matter.
- Trends in eGFR and albuminuria are often more informative than a single KFRE result.
- The optional labs on this page do not change the KFRE score; they are shown only as contextual flags.
- Interpret results cautiously outside the CKD populations in which KFRE is typically used.
What KFRE Adds
KFRE is designed to estimate progression risk in chronic kidney disease using four routinely available variables: age, sex, eGFR, and urine ACR. That makes it helpful when two patients have similar kidney function but very different albuminuria burdens and therefore different longer-term risk patterns.
Reading The Worksheet
The most practical way to use this page is to combine the KFRE estimate with CKD stage, albuminuria category, and trend. The KDIGO heatmap gives a broad prognosis framework, while the KFRE adds a time-based estimate of treated kidney failure. Together they help frame how intensive follow-up or discussion may need to be, without turning the score into an order set.
Important Limits
KFRE is a prediction tool, not a diagnosis and not a full management algorithm. Calibration can differ across populations, and this page uses a fixed 4-variable implementation with contextual lab flags rather than a region selector or 8-variable model. That is why the result is best interpreted as a structured risk estimate to review alongside symptoms, trajectory, and the broader CKD picture.
Sources & Methodology
Last updated:
Methodology
This worksheet uses the 4-variable KFRE equation to estimate 2-year and 5-year treated kidney-failure risk from age, sex, eGFR, and ACR. It is a review-context aid, not a referral rule or a dialysis plan.
The CKD stage and KDIGO heatmap are shown alongside the KFRE estimate so the result can be interpreted as a risk pattern rather than as a stand-alone score.
Sources
- KFRE original validation papers — Basis for the 4-variable kidney failure risk equation.
- KDIGO 2024 CKD guideline (KDIGO) — CKD staging and albuminuria context.
- Kidney health education resources (National Kidney Foundation) — General CKD and kidney-risk context.
Frequently Asked Questions
The KFRE estimates the probability of treated kidney failure, meaning kidney failure managed with dialysis or transplant, over a defined time horizon. It is a prognostic model, not a full CKD management pathway.
Health systems sometimes attach review or triage thresholds to KFRE ranges, but those ranges are program-level tools rather than universal rules. This page shows threshold context only and does not assign a care pathway.
No. On this page, calcium, phosphate, albumin, and bicarbonate are used only for contextual lab flags. The KFRE calculation itself uses age, sex, eGFR, and ACR only.
KFRE is commonly paired with CKD-EPI-based eGFR. As with any estimate, trend and clinical context matter, and very unusual muscle mass or acute illness can make creatinine-based eGFR less representative.
It answers a different question. CKD stage describes baseline kidney function, while KFRE adds an estimate of progression risk. Reading them together is usually more informative than relying on stage alone.
Yes. The model has been validated across many international CKD cohorts. Calibration can vary by population, which is one reason the result should be interpreted as risk context rather than certainty.
More in this topic
Creatinine Clearance Calculator
Calculate creatinine clearance using the Cockcroft-Gault equation. Estimate kidney function for drug dosing and renal assessment.
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.