GFR Calculator
Calculate Glomerular Filtration Rate (eGFR) for kidney function evaluation using the CKD-EPI equation.
eGFR Result
Medical disclaimer. This calculator is for general information and education only. It is not medical advice, not a diagnosis, and not a substitute for professional care. eGFR is an estimate from a single creatinine value. Staging chronic kidney disease requires a sustained reduction over at least three months together with other evidence of damage, so one result is not a diagnosis. Discuss any abnormal value with a clinician rather than acting on it.Speak to a doctor or another qualified clinician about any health decision.Last reviewed .
Frequently asked questions
What is eGFR?
Estimated Glomerular Filtration Rate (eGFR) measures how well your kidneys filter waste from your blood.
Which eGFR equation does this use, and why does it matter?
Modern practice uses the 2021 CKD-EPI creatinine equation, which - unlike the older MDRD and the pre-2021 CKD-EPI - deliberately omits a race coefficient. The change followed evidence that the race adjustment systematically overestimated kidney function in Black patients and delayed referral and transplant listing. Older calculators still applying a race factor will read differently.
What do the CKD stages mean?
Stage 1 is eGFR 90+ with other evidence of kidney damage; stage 2 is 60-89; stage 3a is 45-59; stage 3b is 30-44; stage 4 is 15-29; stage 5 is below 15, which is kidney failure. Staging requires the reduction to be sustained for at least three months, so a single low reading is not a diagnosis.
Why might my eGFR be misleading?
Creatinine comes from muscle, so eGFR over-reads in people with low muscle mass and under-reads in very muscular people. Large meat meals, creatine supplements, pregnancy, amputation and acute illness all shift it. Where creatinine is unreliable, cystatin C based estimates are used instead. Discuss any abnormal result with a clinician rather than acting on it yourself.