Creatinine Clearance Calculator (eGFR)

A creatinine clearance calculator estimates kidney function from serum creatinine, age, weight, and gender. Creatinine is a waste product produced by muscle metabolism that is filtered by the kidneys — higher serum creatinine indicates reduced kidney filtration. eGFR (estimated glomerular filtration rate) is the standard measure of kidney function, expressed in ml/min/1.73m². Our creatinine clearance calculator uses two validated equations: the CKD-EPI 2021 equation for eGFR (the current clinical standard) and the Cockcroft-Gault formula for creatinine clearance (used in drug dosing). Results are classified using the KDIGO 2012 CKD staging system (G1–G5).

1. 1. Enter Your Details: Select your unit system (metric or imperial), creatinine unit (mg/dL or μmol/L), gender, and age. Enter your body weight — this is required for both equations. Height is optional but enables BSA-adjusted creatinine clearance.
2. 2. Enter Your Serum Creatinine: Enter your serum creatinine value from your blood test results. Select mg/dL (US standard) or μmol/L (SI/UK standard) — the calculator converts automatically. Normal ranges are shown as helper text.
3. 3. View eGFR, CrCl, and CKD Stage: Click Calculate eGFR & CrCl to see your eGFR (CKD-EPI 2021), creatinine clearance (Cockcroft-Gault), KDIGO CKD stage with description and management guidance, a visual eGFR gauge, and a full result breakdown.

• CKD-EPI 2021 (Race-Free) — eGFR: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^(−1.200) × 0.9938^Age × 1.012 [if female], where κ = 0.7 (female) or 0.9 (male), α = −0.241 (female) or −0.302 (male). Published by Inker et al. in NEJM 2021. This is the current standard equation recommended by KDIGO and most clinical laboratories.
• Cockcroft-Gault — Creatinine Clearance: CrCl (mL/min) = ((140 − Age) × Weight_kg) / (72 × Scr_mg/dL) × 0.85 [if female]. Published by Cockcroft and Gault in 1976. This formula is still widely used for drug dosing because most pharmacokinetic studies were conducted using this equation.
• BSA-Adjusted CrCl (Mosteller BSA): BSA (m²) = √(Height_cm × Weight_kg / 3600). Adjusted CrCl = CrCl × (1.73 / BSA). Normalising to 1.73 m² body surface area allows comparison across individuals of different body sizes and is required for carboplatin dosing (Calvert formula).

• eGFR (CKD-EPI 2021): Estimated glomerular filtration rate in ml/min/1.73m² using the current KDIGO-recommended race-free equation. Used for CKD staging and monitoring.
• CrCl (Cockcroft-Gault): Creatinine clearance in ml/min. Used for drug dose adjustment — most prescribing information specifies doses based on this formula.
• BSA-Adjusted CrCl: Cockcroft-Gault CrCl normalised to 1.73 m² body surface area. Required for carboplatin dosing and comparison across body sizes. Only shown when height is provided.
• KDIGO CKD Stage: Kidney function stage (G1–G5) based on eGFR, with description of typical findings and recommended management actions at each stage.

eGFR equations are estimates with known limitations. The CKD-EPI equation is less accurate at extremes of age, very high or low muscle mass, unusual diets (e.g. high creatine supplementation or vegan diet), and in acute kidney injury where creatinine is not at steady state. The Cockcroft-Gault formula was derived in a predominantly male, hospitalised population and may overestimate CrCl in obese patients. For clinical decision-making, always interpret eGFR in the context of the full clinical picture, including albuminuria, imaging, and patient history. This calculator is for informational purposes only and does not replace professional medical advice.