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Clinical & Lab Medicine Classic clinical pharmacokinetic estimate Source-mapped educational formula Higher-risk clinical context

Creatinine Clearance Calculator — Cockcroft-Gault

Estimate adult creatinine clearance using the Cockcroft-Gault equation.

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Interactive tool

Calculator

Enter values carefully. Results appear after calculation and should be interpreted with the safety notes and source method on this page.

Source-mapped educational formula

Step 1 — Enter inputs

7 fields required for this tool

Step 2 — Review the result

The result area updates below and keeps safety wording visible.

Result

Complete the form and select Calculate.

About this calculator

Cockcroft-Gault creatinine clearance is commonly used in medication dosing references. The correct weight choice depends on the drug and protocol.

Source-backed
Uses Cockcroft-Gault creatinine clearance: ((140 − age) × weight kg) / (72 × serum creatinine), multiplied by 0.85 for the female equation.
Review status
Source-mapped educational formula
Limitations
Cockcroft-Gault is an estimate and may be inaccurate in acute kidney injury, obesity, underweight, elderly frailty, pregnancy, amputations, dialysis, or rapidly changing creatinine.

Formula and method

CrCl = ((140 − age) × weight in kg) / (72 × Scr mg/dL), multiplied by 0.85 for the female equation.

Medical safety note: This page is for education only and should not replace professional medical advice. For emergencies, medication decisions, or severe symptoms, contact a qualified clinician or local emergency service.

Limitations and when not to rely on this result

  • Cockcroft-Gault is an estimate and may be inaccurate in acute kidney injury, obesity, underweight, elderly frailty, pregnancy, amputations, dialysis, or rapidly changing creatinine.
  • Medication dosing requires the drug label, local renal dosing guidance, body-weight policy, and clinician/pharmacist judgment.
  • Do not use as the only basis for high-risk drug dosing decisions.

Frequently asked questions

Is Cockcroft-Gault the same as eGFR? +

No. Cockcroft-Gault estimates creatinine clearance in mL/min, while eGFR is usually indexed to 1.73 m².

Which weight should I use? +

Use the drug-specific protocol. Some medications use actual, ideal, or adjusted body weight.

Can this be used in acute kidney injury? +

It is unreliable when serum creatinine is changing rapidly.

Is this for children? +

No. Pediatric renal dosing requires pediatric methods.

Why does my lab not report Cockcroft-Gault? +

Many labs report CKD-EPI eGFR instead; Cockcroft-Gault remains common in drug dosing references.