eGFR and creatinine clearance
Kidney function from serum creatinine with the race-free CKD-EPI 2021 equation, placed on the KDIGO stages, with Cockcroft-Gault clearance and BMI.
Example: a 58-year-old man, creatinine 1.1 mg/dL. eGFR is 78 mL/min/1.73 m²: stage G2, mildly decreased.
Creatinine clearance (Cockcroft-Gault) is 75 mL/min. BMI is 25.5 kg/m²: overweight by WHO cut-offs, obese by the Asian cut-offs.
The equations
eGFR (CKD-EPI 2021) = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 if female, where κ is 0.7 for women and 0.9 for men, and α is −0.241 for women and −0.302 for men. The result is in mL/min/1.73 m².
Creatinine clearance (Cockcroft-Gault) = (140 − age) × weight in kg ÷ (72 × Scr), × 0.85 for women, in mL/min. Many drug labels still use it for dose changes.
When not to rely on it
Both equations assume a steady creatinine. They are unreliable in acute kidney injury, pregnancy, very high or low muscle mass, amputation and in children (use a paediatric equation).
KDIGO GFR categories
| Stage | eGFR (mL/min/1.73 m²) | Kidney function |
|---|---|---|
| G1 | 90 or more | Normal or high |
| G2 | 60–89 | Mildly decreased |
| G3a | 45–59 | Mildly to moderately decreased |
| G3b | 30–44 | Moderately to severely decreased |
| G4 | 15–29 | Severely decreased |
| G5 | 0–14 | Kidney failure |
Common questions
Why the 2021 equation?
CKD-EPI 2021 removed the race coefficient of the 2009 equation and is recommended by the US National Kidney Foundation and the American Society of Nephrology.
eGFR or creatinine clearance for drug doses?
Many labels were written with Cockcroft-Gault, so it is still used for dose changes of some drugs; eGFR stages chronic kidney disease. Follow the drug's label.
Which BMI cut-offs are used?
Both: WHO's (25 overweight, 30 obese) and the lower cut-offs advised for Asian adults by the WHO Western Pacific Region and the Indian consensus (23 overweight, 25 obese).
Reviewed by Dr. Herin Shah, MBBS on . For information; it does not replace a doctor's advice.
Sources
- Inker LA et al. New creatinine- and cystatin C-based equations to estimate GFR without race. N Engl J Med 2021;385:1737-49
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD
- Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron 1976;16:31-41
For doctors
Doccine does this for every patient in your clinic.
Doccine keeps each patient's creatinine and eGFR from their lab reports as a trend, and its guidance during the consultation uses the latest eGFR.