GFR Calculator — CKD-EPI 2021 eGFR & Stage

How to use

1. Enter your age and select your sex.
2. Type your serum creatinine and pick the unit from your lab report.
3. Press Calculate eGFR to see the result and the G1–G5 stage table.
4. Discuss the highlighted stage with your clinician.

General information only — not medical, financial or legal advice. Figures cross-checked against public official sources (IRS / HMRC / NHS / WHO guidance); content last reviewed September 2026. For decisions that matter, confirm with a licensed professional in your country.

About this tool

Your estimated glomerular filtration rate (eGFR) is the number nephrologists use to stage chronic kidney disease, and this calculator computes it with the CKD-EPI 2021 race-free creatinine equation — the current US standard that removed the race coefficient from the older 2009 formula. Enter your age, sex and latest serum creatinine from a metabolic panel, in mg/dL or µmol/L, and the page returns your eGFR in mL/min/1.73 m² plus a full G1–G5 stage table with your stage highlighted. Everything is computed locally in your browser; nothing is transmitted or stored. The result is an educational estimate, not medical advice: creatinine-based eGFR is less reliable at extremes of muscle mass, in pregnancy, on dialysis, or with rapidly changing kidney function, so interpret the result with your clinician.

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