eGFR (estimated glomerular filtration rate) estimates how much blood your kidneys filter per minute, normalized to body surface area. Normal eGFR is 90–120 mL/min/1.73m². Below 60 for more than 3 months defines chronic kidney disease. It's calculated from serum creatinine, age, and sex.

Why was the race coefficient removed in the race-free equation?

The NKF and ASN task force determined that race-based adjustments were problematic: race is a social construct, not a biological variable. The adjusted coefficients had led to underdiagnosis of kidney disease in Black patients. The CKD-EPI race-free equation uses a single formula for all patients.

What CKD stage requires dialysis?

Dialysis is typically considered in Stage 5 (eGFR < 15), though the decision depends on symptoms, not just the number. Some patients start dialysis at eGFR 5–10 when they develop symptoms like fluid overload, nausea, or hyperkalemia. Pre-emptive kidney transplant is preferred when available.

eGFR can improve if the underlying cause is treated: controlling blood pressure, managing diabetes, stopping nephrotoxic drugs, or relieving urinary obstruction. However, most CKD represents permanent nephron loss and is progressive. The goal is usually to slow decline rather than reverse it.

Is eGFR accurate in elderly patients?

eGFR can overestimate kidney function in elderly patients with low muscle mass (less creatinine production). Cystatin C-based equations may be more accurate in this population. An eGFR of 50 in an 85-year-old may reflect age-related decline rather than disease.

What medications need dose adjustment for low eGFR?

Many medications require dose adjustment when eGFR drops below 60, including antibiotics (aminoglycosides, vancomycin), diabetes drugs (metformin below 30), contrast agents, and opioids. Always inform your pharmacist and doctors about your eGFR so they can adjust doses appropriately.

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.

⚠️ Medical Disclaimer: This calculator is for educational purposes only and uses the CKD-EPI 2021 race-free equation. It does not replace professional medical evaluation. Always consult a healthcare provider for kidney function assessment.

Serum Creatinine

mg/dL

Age

yrs

Sex

Estimated GFR (CKD-EPI 2021)

mL/min/1.73 m²

Stage 1 — Normal

Normal or high kidney function

eGFR

92 mL/min/1.73m²

CKD-EPI 2021 race-free

CKD Stage

Stage 1

Normal

Kidney Function Gauge

01530456090120+

CKD Staging Reference

Stage	GFR Range	Description	Action
Stage 1 ◀	≥ 90	Normal or high	Monitor if risk factors present
Stage 2	60–89	Mildly decreased	Estimate progression risk; treat risk factors
Stage 3a	45–59	Mild-moderate decrease	Review trend, albuminuria, meds, and risk factors
Stage 3b	30–44	Moderate-severe decrease	Consider nephrology input and medication review
Stage 4	15–29	Severely decreased	Advanced CKD evaluation and kidney-care planning
Stage 5	< 15	Kidney failure	Specialist management based on symptoms and overall status

eGFR by Age (at current creatinine)

Age	eGFR	Stage
30	104	Stage 1
40	98	Stage 1
50 (you)	92	Stage 1
60	86	Stage 2
70	81	Stage 2
80	76	Stage 2

Planning notes, formulas, and examples

About the eGFR Calculator

The eGFR Calculator estimates glomerular filtration rate from serum creatinine, age, and sex using the CKD-EPI race-free creatinine equation. It is a quick way to translate a creatinine result into the standardized mL/min/1.73 m² value commonly used in kidney-function reporting.

This page is most useful for reviewing where a creatinine result falls in the usual kidney-function bands and for understanding how age and sex affect the estimate. It uses the race-free equation rather than older formulas that included a race coefficient.

The result is only one part of kidney assessment. eGFR by itself does not complete CKD staging without urine albumin data, and the estimate can be less reliable in acute kidney injury, very unusual muscle mass, pregnancy, and some other clinical settings.

When This Page Helps

Creatinine alone is hard to interpret without context. This page converts it into the standard CKD-EPI race-free estimate, keeps the stage bands visible, and makes it easier to review whether the result is broadly normal, mildly reduced, or clearly in an advanced CKD range.

How to Use the Inputs

Enter your serum creatinine level from your blood test (mg/dL).
Enter your age in years.
Select your sex (biological sex affects the calculation).
View your estimated GFR and CKD stage.
Review the CKD staging reference table.
Consult your doctor for interpretation and any needed follow-up.

Formula used

CKD-EPI Race-Free Equation:

Female:
• If Scr ≤ 0.7: eGFR = 142 × (Scr/0.7)^(−0.241) × 0.9938^age
• If Scr > 0.7: eGFR = 142 × (Scr/0.7)^(−1.200) × 0.9938^age

Male:
• If Scr ≤ 0.9: eGFR = 142 × (Scr/0.9)^(−0.302) × 0.9938^age
• If Scr > 0.9: eGFR = 142 × (Scr/0.9)^(−1.200) × 0.9938^age

CKD Stages:
• Stage 1: GFR ≥ 90 (Normal)
• Stage 2: 60–89 (Mildly decreased)
• Stage 3a: 45–59 (Mild-moderate)
• Stage 3b: 30–44 (Moderate-severe)
• Stage 4: 15–29 (Severely decreased)
• Stage 5: < 15 (Kidney failure)

Example Calculation

Result: eGFR = 71 mL/min/1.73m² — Stage 2 (Mildly Decreased)

Using the CKD-EPI race-free male equation with Scr = 1.2 mg/dL (>0.9): eGFR = 142 × (1.2/0.9)^(−1.200) × 0.9938^55 ≈ 71.4, which rounds to 71 mL/min/1.73m². That falls in the stage 2 range. CKD staging still depends on whether the reduction is persistent and whether albuminuria or other kidney abnormalities are present.

Tips & Best Practices

eGFR is most useful when creatinine is stable; acute kidney injury can make the estimate misleading.
Muscle mass affects creatinine production, so very muscular, frail, amputee, or cachectic patients may get less reliable creatinine-based estimates.
Kidney risk is interpreted with both eGFR and albuminuria, not eGFR alone.
Small age-related declines can occur even without progressive kidney disease, so trend matters more than a single borderline value.
Medication dosing, nephrology referral, and CKD diagnosis depend on the broader history and follow-up testing, not just the number on this page.
If kidney disease is suspected, urine albumin testing and repeat creatinine measurement usually matter as much as the one-time eGFR estimate.
Avoiding unnecessary nephrotoxins such as NSAIDs can be important when kidney function is already reduced or at risk.

The CKD-EPI Race-Free Equation

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) published the race-free equation, endorsed by the NKF and ASN. It replaced the older CKD-EPI equation that used a race coefficient. The equation was developed from a large, diverse population and validated across multiple cohorts.

CKD Staging and Prognosis

CKD staging combines eGFR with albuminuria (protein in urine) to create a risk matrix. An eGFR of 55 with normal urine protein (stage 2) has a much better prognosis than an eGFR of 55 with heavy proteinuria (high risk for progression). Both values should be assessed together for comprehensive kidney health evaluation.

When to See a Nephrologist

Referral is recommended for: eGFR below 30 (stage 4–5), persistent eGFR decline >5/year, significant proteinuria (urine albumin-to-creatinine ratio >300), resistant hypertension with reduced eGFR, or unexplained kidney function abnormalities. Early nephrology involvement improves outcomes and preparation for renal replacement therapy if needed.

Sources & Methodology

Last updated: March 27, 2026

Methodology

This page applies the CKD-EPI 2021 race-free creatinine equation using age, sex, and serum creatinine in mg/dL, then reports the result as eGFR in mL/min/1.73 m². It also groups the estimate into the usual G-stage bands so the number can be reviewed in the same staging language used in kidney-function reporting.

The result is intended as a kidney-function estimate rather than a complete CKD diagnosis. Chronic kidney disease staging also depends on persistence over time and albuminuria, and creatinine-based estimates can be less reliable in acute kidney injury, pregnancy, unusual muscle mass, and other settings where creatinine generation or steady-state assumptions are altered.

Sources

New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race (New England Journal of Medicine) — CKD-EPI 2021 publication describing the current race-free creatinine equation.
KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (Kidney Disease: Improving Global Outcomes) — Guideline context that CKD risk assessment uses both GFR and albuminuria rather than eGFR alone.

Frequently Asked Questions

eGFR (estimated glomerular filtration rate) estimates how much blood your kidneys filter per minute, normalized to body surface area. Normal eGFR is 90–120 mL/min/1.73m². Below 60 for more than 3 months defines chronic kidney disease. It's calculated from serum creatinine, age, and sex.