Creatinine Clearance Calculator (Cockcroft-Gault Equation)
Estimates Creatinine Clearance (CrCl in mL/min) for renal drug dose adjustment across adult patients.
⚠️ Educational Calculation & Clinical Safety Safeguard: Cockcroft-Gault requires stable serum creatinine; do not rely on a single SCr value during acute kidney injury (AKI). Educational calculations do not replace clinician assessment, patient-specific laboratory monitoring, or institutional prescribing protocols.
Interactive Calculator
Allowed physiological/compounding range: 18 to 110 years
Allowed physiological/compounding range: 25 to 250 kg
Allowed physiological/compounding range: 0.2 to 20 mg/dL
Allowed physiological/compounding range: 0 to 1 1=Male, 0=Female
Calculated Output (mL/min)
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Step-by-Step Mathematical Derivation & Explanation:
Validated Formula & Conversion Rules
CrCl (mL/min) = [(140 − Age) × Weight (kg)] / [72 × SCr (mg/dL)] × (0.85 if Female)Worked Clinical Example
65-year-old Male, Weight 72 kg, SCr 1.5 mg/dL: CrCl = [(140 − 65) × 72] / (72 × 1.5) = 75 / 1.5 = 50.0 mL/min.
Rounding Rules, Clinical Interpretation, Assumptions & Known Limitations
- 1. Purpose: Estimates Creatinine Clearance (CrCl in mL/min) for renal drug dose adjustment across adult patients.
- 2. Required Inputs & Validated Units: Patient Age (years, range 18–110), Dosing Weight (kg, range 25–250), Serum Creatinine (SCr) (mg/dL, range 0.2–20), Biological Sex (1 = Male, 0 = Female) (1=Male, 0=Female, range 0–1)
- 3. Output Unit:
mL/min - 4. Result Interpretation Notes: Estimates Creatinine Clearance (CrCl in mL/min) via the Cockcroft-Gault equation — the historical reference standard for drug-labelling renal dose adjustments.
- 5. Rounding Guidance: Round CrCl to nearest whole mL/min or 1 decimal place.
- 6. Mathematical & Clinical Assumptions: Assumes stable, steady-state serum creatinine and normal age-appropriate muscle mass.
- 7. Known Limitations & Contraindications to Formula Use: Do NOT rely on Cockcroft-Gault in acute kidney injury (AKI) with rapidly rising SCr, severe cachexia/cirrhosis, amputees, or pregnancy.
- 8. Supporting Compendial & Clinical References: Indian Pharmacopoeia (IP 2022), National Formulary of India (NFI), British National Formulary (BNF), and NCBI Bookshelf Clinical Pharmacology Compendia.