Estimates renal function using Cockcroft-Gault (creatinine clearance, useful for renal drug dosing) and CKD-EPI 2021 race-free (eGFR, used for CKD staging).
Cockcroft-Gault: CrCl = [(140 − age) × weight(kg) × (0.85 if female)] / (72 × SCr(mg/dL)). CKD-EPI 2021 (race-free) is used for eGFR/CKD staging. Both are estimates — unstable renal function, extremes of body size, amputation, or altered muscle mass reduce accuracy; use with clinical judgment, especially for narrow-therapeutic-index drugs.