Free clinical tool

Renal Function Calculator

Estimate creatinine clearance with Cockcroft-Gault for drug dosing, alongside MDRD and CKD-EPI 2021 eGFR.

Patient

Sex

Age

years old

Weight

Cockcroft-Gault uses the weight entered here.

Creatinine

How these are calculated

Cockcroft-Gault creatinine clearance¹

CrCl (mL/min) = 1.23 × (140 − age) × weight (kg) ÷ SCr (µmol/L)
For females, multiply the result by 0.85.

MDRD, IDMS-traceable, race-free²

eGFR (mL/min/1.73 m²) = 175 × (SCr ÷ 88.4)^−1.154 × age^−0.203 × 0.742 (if female)

CKD-EPI 2021, race-free³

eGFR (mL/min/1.73 m²) = 142 × min(SCr/κ, 1)^α × max(SCr/κ, 1)^−1.200 × 0.9938^age × 1.012 (if female)

SCr in mg/dL (µmol/L ÷ 88.4); κ = 0.7 for females, 0.9 for males; α = −0.241 for females, −0.302 for males.

Drug dosing: MDRD and CKD-EPI eGFR are not interchangeable with Cockcroft-Gault creatinine clearance. Estimate kidney function with the equation the dosing recommendation was developed with, which for most drugs is Cockcroft-Gault.

No race coefficient: race-based eGFR adjustment is no longer recommended, and none of these results apply one.^4–6

Sex: the equations classify patients as male or female, as they were derived. Assess each patient individually.

References

Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron 1976;16(1):31-41. PubMed
Levey AS, Coresh J, Greene T, et al. Using standardized serum creatinine values in the Modification of Diet in Renal Disease study equation for estimating glomerular filtration rate. Ann Intern Med 2006;145(4):247-54. PubMed
Inker LA, Eneanya ND, Coresh J, et al. New creatinine- and cystatin C-based equations to estimate GFR without race. N Engl J Med 2021;385(19):1737-49. PubMed
Delgado C, Baweja M, Crews DC, et al. A unifying approach for GFR estimation: recommendations of the NKF-ASN task force on reassessing the inclusion of race in diagnosing kidney disease. Am J Kidney Dis 2022;79(2):268-88. PubMed
Marzinke MA, Greene DN, Bossuyt PM, et al. Limited evidence for use of a black race modifier in eGFR calculations: a systematic review. Clin Chem 2022;68(4):521-33. PubMed
Auguste BL, Nadeau-Fredette AC, Parekh RS, et al. A Canadian commentary on the NKF-ASN task force recommendations on reassessing the inclusion of race in diagnosing kidney disease. Kidney Med 2024;6(1):100746. PubMed

Nothing you enter is saved or sent anywhere. These estimates support, and never replace, clinical judgement.