Creatinine Clearance Calculator — Cockcroft-Gault CrCl

Answer: About 57.3 mL/min.

[(140 − 70) × 80 × 1] ÷ (0.814 × 120) = 5600 ÷ 97.68 = 57.3 mL/min.

Answer: About 51.6 mL/min.

[(140 − 65) × 70 × 0.85] ÷ (72 × 1.2) = 4462.5 ÷ 86.4 = 51.6 mL/min.

Answer: Adjusted weight about 82.28 kg and CrCl about 80.9 mL/min.

IBW 70.46 kg; adjusted weight = 70.46 + 0.4 × (100 − 70.46) = 82.28 kg; CrCl = [(140 − 60) × 82.28] ÷ (0.814 × 100) = 80.9 mL/min.

It is an estimated creatinine clearance in mL/min calculated from age, selected weight, serum creatinine, and the Cockcroft-Gault sex factor.

• The result is an estimate rather than a timed urine measurement or directly measured GFR.
• It is not a diagnosis, CKD stage, medication dose, or universal dosing category.
• Use it only when the current medicine label, dosing reference, pharmacist, prescriber, or local protocol requires Cockcroft-Gault CrCl.

A result of 57.3 mL/min is the calculator estimate produced from the entered values and selected weight method.

It uses the adult Cockcroft-Gault equation and reports estimated creatinine clearance in mL/min.

• Using mg/dL: CrCl = [(140 − age) × weight kg × sex factor] ÷ [72 × serum creatinine mg/dL].
• Using µmol/L: CrCl = [(140 − age) × weight kg × sex factor] ÷ [0.814 × serum creatinine µmol/L].
• The equation uses a factor of 1.0 for male and 0.85 for female.

70 years, 80 kg, male, SCr 120 µmol/L → about 57.3 mL/min.

Use the unit shown on the pathology result. The calculator supports both units and changes the equation automatically.

• Australian pathology commonly reports serum creatinine in µmol/L, while many international references use mg/dL.
• Choosing the wrong unit can create a major calculation error.
• For a rough check only, serum creatinine in mg/dL is approximately µmol/L divided by 88.4.

106 µmol/L is approximately 1.20 mg/dL, not 106 mg/dL.

No. They are different estimates and should not be substituted automatically.

• Cockcroft-Gault estimates creatinine clearance as an absolute mL/min value and includes a selected weight.
• Laboratory eGFR is commonly reported in mL/min/1.73 m² and is calculated with a different equation.
• Newer eGFR methods may be appropriate for many medicines, while some labels and references still specify Cockcroft-Gault CrCl. Use the method named by the current source.

If a medicine monograph specifies Cockcroft-Gault CrCl, do not replace it with the laboratory eGFR without checking the guidance.

Use the weight method required by the current medicine reference or local protocol. The calculator shows options but does not choose the clinically correct one.

• You can enter a protocol-selected kilogram weight directly or compare actual, Devine ideal, and adjusted weight.
• The adjusted option uses IBW + 0.4 × (actual weight − IBW); the factor and method are not universal.
• The result records the selected method so the calculation can be checked.

No. It calculates arithmetic only and does not select a medicine, dose, interval, threshold, or dialysis adjustment.

• A medicine reference may use CrCl bands, but those bands and actions are product-specific.
• The final decision may also depend on indication, renal trend, toxicity, therapeutic drug monitoring, dialysis, and clinical context.
• Use the exact renal estimate and thresholds stated in the current medicine source.

Be cautious when serum creatinine is changing rapidly or when creatinine does not reliably reflect filtration.

• Examples include acute kidney injury, dialysis, pregnancy, severe frailty, low muscle mass, and extremes of body size.
• A single creatinine-based estimate can lag behind rapid renal change.
• Measured clearance, measured GFR, cystatin C, or another estimate may be needed depending on the clinical question.

They may use different creatinine units, weight methods, rounding rules, height formulas, or automatic assumptions.

• Actual, ideal, adjusted, and directly entered protocol weights can produce different estimates.
• Some calculators round intermediate values while others round only the final result.
• Compare the equation, creatinine unit, selected weight, sex factor, and rounding before comparing outputs.