Creatinine Clearance for Drug Dosing
Enter age, weight, sex, and serum creatinine to compute CrCl via Cockcroft-Gault and see which renal impairment tier applies for drug dosing.
Use the Creatinine Clearance for Drug Dosing
Patient Parameters
For educational use only. Not a substitute for clinical judgment.
Fill in patient data and press Calculate.
Estimated CrCl
mL/min
Formula Breakdown
CrCl = [(140 − Age) × Weight(kg)] ÷ [72 × SCr(mg/dL)] × sex factor
Renal Dosing Tiers
Active tier is highlighted. Confirm exact cutoffs in drug prescribing information.
Summary
The Cockcroft-Gault equation is the standard formula used in drug labeling and FDA guidance for renal dose adjustment. This tool computes creatinine clearance (CrCl) in mL/min from patient age, body weight, sex, and serum creatinine, then maps the result to standard dosing tiers (normal, mild, moderate, severe impairment, and dialysis). It supports actual, ideal, and adjusted body weight selection — a critical distinction for obese patients — and accepts serum creatinine in either mg/dL or µmol/L. All computation runs in the browser; no patient data is transmitted.
How it works
- Enter the patient's age in years, body weight, and serum creatinine level.
- Select the appropriate weight type: actual body weight for non-obese patients, ideal body weight for obese patients per many guidelines, or adjusted body weight (IBW + 0.4 × excess) for patients significantly above IBW.
- Select biological sex — the formula multiplies by 0.85 for females to account for lower average muscle mass.
- Choose serum creatinine units (mg/dL or µmol/L); the tool converts automatically.
- CrCl is computed: [(140 − Age) × Weight(kg)] ÷ (72 × SCr in mg/dL) × (0.85 if female).
- The result is displayed in mL/min alongside the matched dosing impairment tier and clinical interpretation.
Use cases
- Selecting an appropriate dose for renally cleared drugs before ordering.
- Determining which renal dosing tier applies when drug labeling references CrCl thresholds.
- Adjusting weight input method for obese patients using IBW or adjusted body weight.
- Verifying pharmacy dosing recommendations at the bedside.
- Teaching Cockcroft-Gault pharmacokinetics in clinical pharmacology courses.
- Pre-rounding renal function review in hospital or ICU settings.
- Screening patients for drugs contraindicated below specific CrCl cutoffs.
- Converting serum creatinine from µmol/L (SI) to mg/dL for the formula.