eGFR Calculator (CKD-EPI 2021)
Estimate your kidney function from serum creatinine, age and sex using the race-free CKD-EPI 2021 equation, and see your CKD stage. It is free and nothing you enter is stored.
This tool is for education only. It is not a diagnosis or a treatment plan. Never stop or change a prescribed medicine without your doctor. Nothing you enter is stored or sent anywhere.
The CKD-EPI 2021 formula
eGFR = 142 × min(Scr/κ, 1)α × max(Scr/κ, 1)-1.200 × 0.9938age × 1.012 (if female). Scr is serum creatinine in mg/dL (divide µmol/L by 88.4). κ is 0.7 for women and 0.9 for men; α is -0.241 for women and -0.302 for men. The 2021 version no longer uses race.
Kidney function stages
| eGFR (mL/min/1.73 m²) | Stage | Meaning |
|---|---|---|
| 90 or more | G1 | Normal or high |
| 60 to 89 | G2 | Mildly reduced |
| 45 to 59 | G3a | Mildly to moderately reduced |
| 30 to 44 | G3b | Moderately to severely reduced |
| 15 to 29 | G4 | Severely reduced |
| Under 15 | G5 | Kidney failure range |
Urine albumin (UACR)
If you have a UACR result, under 30 mg/g is A1 (normal), 30 to 300 is A2 (moderately increased) and over 300 is A3 (severely increased). Stages follow KDIGO.
Normal creatinine
Typical serum creatinine is about 0.7 to 1.2 mg/dL in men and 0.5 to 1.0 mg/dL in women, but labs differ. Kidney disease is confirmed when results stay low for 3 months.
Common questions
90 or more is normal for most adults. eGFR falls slowly with age, so 60 to 89 can be normal for older adults if there is no other sign of kidney damage.
The 2021 CKD-EPI equation was refitted without a race term to give fairer estimates for everyone.
Diabetes is the commonest cause of kidney strain. Checking sugar and blood pressure regularly protects your kidneys.
No. It must stay low for 3 months, and your doctor will repeat the test and may check urine albumin.
Check with your doctor before starting any supplement if your eGFR is below 60.