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eGFR calculator (CKD-EPI 2021)
eGFR estimates how efficiently your kidneys filter blood, based on serum creatinine, age and sex. We use the CKD-EPI 2021 formula, which does not include race.
Calculations run in your browser. We do not send or store anything.
Result
Fill in the fields to see the result.
How we calculate it
CKD-EPI 2021 formula (Inker et al.): eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 (women). For women κ = 0.7 and α = −0.241, for men κ = 0.9 and α = −0.302. Scr is creatinine in mg/dL (µmol/L ÷ 88.4).
The G1–G5 categories come from the KDIGO guidelines.
Limitations
- The formula assumes typical muscle mass. High muscle mass, creatine supplementation, a high-protein meal before the test or dehydration raise creatinine and lower the result.
- The formula is intended for adults in a stable condition. It is not used in acute kidney injury, in pregnancy or in children.
- If in doubt, a doctor may order cystatin C or a urine protein or albumin test.
Sources
Read more
- eGFR and Age: How Much Does It Fall After 40 and When Is It a Problem?
- Cystatin C vs Creatinine: Which Test Measures Kidney Function Better?
- Can Creatine Raise Creatinine Even With Healthy Kidneys?
- Can Dehydration Raise Creatinine Even With Healthy Kidneys?
- Creatinine and eGFR (Estimated Glomerular Filtration Rate)