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GFR Calculator

Estimate kidney function (eGFR) from serum creatinine, using the 2021 race-free CKD-EPI equation.

years
mg/dL

Formula: 2021 CKD-EPI creatinine equation (race-free).

A screening estimate only — kidney function assessment requires a clinician's interpretation alongside other tests.

Worth Knowing

This estimates glomerular filtration rate — a core measure of kidney function — from serum creatinine using the 2021 CKD-EPI equation, which was revised specifically to remove the race coefficient earlier versions included. eGFR is an estimate, not a direct measurement, and creatinine is affected by muscle mass, so it can misread very muscular or very frail people. It's meant to be interpreted by a clinician alongside other tests; this tool is for reference and education only.

How to Use

  1. Enter Gender into the first field of the GFR Calculator.
  2. Fill in the rest: Age, Serum creatinine.
  3. Your result appears instantly as you type — there's no submit button or page reload.
  4. A screening estimate only — kidney function assessment requires a clinician's interpretation alongside other tests.

Formula

2021 CKD-EPI creatinine equation (race-free).

Frequently Asked Questions