What formula is used for creatinine clearance?

The Cockcroft-Gault equation: CrCl (mL/min) = [(140 - Age) x Weight (kg) x (0.85 for female)] / (72 x Serum Creatinine (mg/dL)). It estimates creatinine clearance (CrCl), which typically exceeds true GFR by 10–20% due to tubular secretion, but serves as the standard metric in FDA drug dosing labeling.

Which drugs require renal dose adjustment?

Many renally cleared drugs require adjustment, including selected antibiotics such as amoxicillin, clarithromycin, cephalexin, ciprofloxacin, and vancomycin. Exact thresholds are drug- and indication-specific; use current prescribing information.

Should I use actual or ideal body weight?

Use actual body weight for non-obese patients. For obese patients (actual > 30% above IBW), many references recommend adjusted body weight. This tool uses the weight you enter, so apply clinical judgment when selecting the value.

Are these recommendations definitive?

No. This tool is a quick reference only. Always consult current prescribing information, a clinical pharmacist, or authoritative references such as Lexicomp or Micromedex before making dosing decisions.

What are the CrCl cutoffs used?

Normal: >= 60 mL/min, Mild impairment: 30-59 mL/min, Moderate: 15-29 mL/min, Severe: < 15 mL/min (non-dialysis), Dialysis (ESRD): patient on renal replacement therapy.

Is my patient data stored?

No. All calculations are performed entirely in your browser. No data is sent to any server.

Renal Dose Adjustment Guide

Calculate creatinine clearance via Cockcroft-Gault, then look up dose adjustments for ~25 common drugs across CrCl ranges.

Step 1 — Calculate Creatinine Clearance (Cockcroft-Gault)

Age (years)

Weight (kg)

Serum Creatinine (mg/dL)

Sex

Male Female

Step 2 — Dose Adjustment Reference Table

Approximately 25 common drugs. Search by drug name or class. Highlighted column matches your calculated CrCl category.

Drug	Class	Normal ≥60	Mild 30-59	Moderate 15-29	Severe <15	Dialysis ESRD

This table is a quick reference only. Always verify with current prescribing information before making clinical decisions.

Summary

Enter patient demographics and serum creatinine to compute estimated creatinine clearance (CrCl) using the Cockcroft-Gault equation. The tool then displays a filterable reference table of approximately 25 commonly used drugs with dose modification guidelines for normal, mild, moderate, severe renal impairment, and dialysis.

How it works

Enter patient age, weight, sex, and serum creatinine.
The tool computes creatinine clearance with the Cockcroft-Gault equation: CrCl = [(140 − age) × weight × (0.85 if female)] / (72 × serum creatinine).
The resulting CrCl value highlights the matching dosing column in the drug table.
Filter or search the ~25-drug reference to see dose changes for each impairment stage.
Confirm any change against current prescribing information before dosing.

Use cases

Screen drug regimens for patients with chronic kidney disease.
Quickly identify drugs that require dose reduction or avoidance in renal failure.
Teach pharmacokinetics and renal drug dosing to students and trainees.
Support clinical decision-making at the bedside or in ambulatory care.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu