Health & Fitness Calculators
GFR Calculator
Estimate kidney function (eGFR).
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About the GFR Calculator
Estimated glomerular filtration rate (eGFR) is the key measure of kidney function. Enter your sex, age, and serum creatinine and the calculator uses the race-free CKD-EPI 2021 equation to estimate your eGFR and the corresponding chronic kidney disease stage. It's the same formula labs use — a helpful reference, though only a clinician can interpret it in context.
How to use the GFR Calculator
- 01Enter your sex, age, and serum creatinine.
- 02Read the result instantly — it recalculates as you type.
- 03Adjust the numbers to model different scenarios.
Frequently asked questions
What is a normal GFR?
An eGFR of 90+ mL/min/1.73m² is normal (stage G1). Below 60 for three months suggests chronic kidney disease. Discuss results with a doctor.
Which equation is this?
The 2021 CKD-EPI creatinine equation, which removed the race coefficient. It uses creatinine, age, and sex.