eGFR calculator (CKD-EPI 2021)
Estimated GFR by the race-free CKD-EPI 2021 creatinine equation, with CKD stage.
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This is a reference implementation of a published formula, provided for use by qualified healthcare professionals. It does not diagnose, does not account for the individual circumstances of any patient, and is not a recommendation for treatment. Confirm every result against your own institutional guidance before acting on it. Clinical judgement always takes precedence over a calculator.
About this calculation
The 2021 CKD-EPI creatinine equation estimates glomerular filtration rate from creatinine, age and sex. It replaced the earlier equation specifically to remove the race coefficient, which had no physiological basis and systematically overestimated kidney function in Black patients, delaying referral and transplant listing.
Formula
eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 [if female], where κ = 0.7 (female) or 0.9 (male) and α = −0.241 (female) or −0.302 (male)
- Source
- Inker LA et al., New England Journal of Medicine — CKD-EPI creatinine equation (2021)
- Methodology version
- 1.0.0
- Last reviewed
- 2026-10-28
What this does not account for
- eGFR is reported indexed to 1.73 m² of body surface area. For drug dosing at the extremes of body size it must be de-indexed to the patient’s own BSA, or Cockcroft-Gault used instead.
- The equation assumes creatinine is at steady state and is not valid in acute kidney injury.
- It is unreliable where creatinine generation is atypical: substantially reduced or increased muscle mass, amputation, pregnancy, or a very high-protein or vegetarian diet.
- Most drug labels specify creatinine clearance by Cockcroft-Gault, not eGFR. The two are not interchangeable.
- CKD staging requires the abnormality to be present for at least three months. A single result does not stage anyone.