eGFR calculator
Estimate the glomerular filtration rate (eGFR) with the race-free CKD-EPI 2021 creatinine equation, from serum creatinine, age, and sex. The result is in mL/min/1.73m² and is mapped to the KDIGO GFR categories.
Estimated eGFR
Enter the values to see the result.
This tool assists calculation. It does not replace clinical judgement and is not a treatment instruction. Check against your institution protocol, reference ranges, and prescribing information. Clinical decisions belong to the treating clinician.
Interpreting the result
- G5 — kidney failure — eGFR below 15 mL/min/1.73m².
- G4 — severely decreased
- G3b — moderately to severely decreased
- G3a — mildly to moderately decreased
- G2 — mildly decreased — Only counts as CKD with a marker of kidney damage.
- G1 — normal or high — Only counts as CKD with a marker of kidney damage.
Formula
eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^Age × (1.012 if female), with κ = 0.7 (female) or 0.9 (male) and α = −0.241 (female) or −0.302 (male). Creatinine is converted to mg/dL.
Frequently asked questions
How is CKD-EPI 2021 different from the older equation?
The CKD-EPI 2021 equation removed the race coefficient and uses only creatinine, age, and sex. It is the version many bodies now recommend.
What eGFR is abnormal?
By KDIGO, an eGFR under 60 mL/min/1.73m² for more than 3 months suggests chronic kidney disease. G1 and G2 count as CKD only with a marker of kidney damage.
Does this replace a doctor?
No. It is a supportive estimate to read in clinical context. The decision belongs to the treating clinician.