GFR Calculator (Kidney Function)
Enter your age, sex and blood creatinine result to estimate how well your kidneys filter blood, using the CKD-EPI 2021 equation.
Lab Values
Estimated glomerular filtration rate (eGFR) from serum creatinine, age and sex using the CKD-EPI 2021 equation, with CKD stage.
Formula
eGFR = 142 × min(Scr/κ,1)^α × max(Scr/κ,1)^−1.200 × 0.9938^age × 1.012 (female), κ = 0.7 female / 0.9 male.
Reference Values
- •G1: ≥90 normal
- •G2: 60–89 mild
- •G3a/b: 45–59 / 30–44
- •G4: 15–29 severe
- •G5: <15 failure
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FAQ
Common questions about GFR Calculator
How we calculate this
We use the standard published formula for this calculation, and we show the working so you can check it.
Spotted a mistake? Tell us and we'll check it within a few days. See how we check our calculators.
Medical disclaimer
This tool gives a general estimate for information only. It is not medical advice and cannot diagnose a condition. Talk to a doctor, midwife or other qualified professional about your own situation.