2021 CKD-EPI creatinine equation (race-free)
eGFR = 142 × min(SCr/κ,1)α × max(SCr/κ,1)−1.200 × 0.9938Age × 1.012 [if female]
κ = 0.7 female / 0.9 male; α = −0.241 female / −0.302 male. Serum creatinine should be standardized/IDMS-traceable.
| G category | eGFR (mL/min/1.73 m²) |
|---|
| G1 | ≥90 |
| G2 | 60–89 |
| G3a | 45–59 |
| G3b | 30–44 |
| G4 | 15–29 |
| G5 | <15 |
eGFR is an estimate, not a direct measurement. CKD staging requires clinical context and evidence of chronicity. For ages 18–25, NIDDK also recommends considering the CKiD U25 equation.