About this tool
The eGFR Calculator estimates your estimated glomerular filtration rate — a measure of how well your kidneys filter blood — from a serum creatinine result, your age and your sex. It uses the 2021 CKD-EPI creatinine equation, the current race-free standard, and runs entirely in your browser.
The formula is eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 (if female), where Scr is serum creatinine in mg/dL, κ is 0.7 for females and 0.9 for males, and α is −0.241 for females and −0.302 for males. If your lab reports creatinine in µmol/L, choose that unit and it is converted to mg/dL by dividing by 88.42 before the calculation. The result is expressed in mL/min/1.73m², the standardized unit for filtration rate.
The calculator also classifies the result into a CKD (chronic kidney disease) stage: G1 is 90 or above, G2 is 60–89, G3a is 45–59, G3b is 30–44, G4 is 15–29 and G5 is below 15. This is general information and not medical advice — eGFR is an estimate that a clinician interprets alongside your history, other tests and a persistent pattern over time. Always consult a doctor about your kidney health.