How is creatinine clearance calculated?

The Cockcroft-Gault equation: CrCl = [(140 − age) × weight (kg)] / [72 × serum creatinine (mg/dL)] × 0.85 if female. It estimates creatinine clearance in mL/min and is not adjusted for body surface area, unlike eGFR.

What is the difference between CrCl and eGFR?

CrCl (Cockcroft-Gault) estimates actual creatinine clearance in mL/min using weight, while eGFR (CKD-EPI) estimates glomerular filtration rate normalized to 1.73 m² BSA. CrCl is still required by many drug labels for dose adjustment, particularly older medications. CrCl slightly overestimates true GFR because of tubular creatinine secretion.

Which weight should be used for Cockcroft-Gault?

Use actual body weight for most patients. For obese patients (>120% IBW), the original Cockcroft-Gault was derived using actual weight, but many pharmacists use adjusted body weight [IBW + 0.4 × (actual − IBW)] to avoid overestimation. There is no consensus on the best approach for obesity.

When should you use CrCl instead of eGFR?

Use CrCl (Cockcroft-Gault) when drug labels specifically reference it for dose adjustment (e.g., DOACs, enoxaparin, many antibiotics). Use eGFR for CKD staging and monitoring. The values may differ significantly, especially in elderly, obese, or cachectic patients.

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Creatinine Clearance (Cockcroft–Gault)

Estimate creatinine clearance (CrCl) in mL/min using the Cockcroft–Gault equation.

Eingaben

Geschlecht

Alter (Jahre)

Gewicht (kg)

Serum creatinine Units: mg/dL

Creatinine units

Rounding Many drug labels use whole-number CrCl cutoffs.

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Enter inputs to calculate CrCl.

Haftungsausschluss: Nur zu Bildungszwecken. Kein Ersatz für klinisches Urteil. Confirm the method required by the specific medication label and your institution’s policy.

Klinische Hinweise

Cockcroft–Gault estimates creatinine clearance (not eGFR) and is commonly referenced in drug dosing and clinical trials.
Performance can be poor in extremes of body size, very low muscle mass, unstable renal function (AKI), and pregnancy.
Units matter: ensure creatinine is in mg/dL (this tool converts from µmol/L if selected).

Interpretation (rough)

Renal dosing cutoffs vary by medication. A common framework:

≥ 60Often “mild/no impairment”

30–59Moderate impairment (many dose adjustments)

< 30Severe impairment (many contraindications)

< 15Kidney failure range

References

Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976.

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Über dieses Tool

What Is Creatinine Clearance (CrCl)?

Creatinine clearance (CrCl) estimated by the Cockcroft-Gault equation is a widely used measure of kidney function, particularly for medication dose adjustment. Published in 1976, the formula uses age, weight, sex, and serum creatinine to estimate the rate at which creatinine is cleared from the blood (mL/min). Unlike eGFR, CrCl from Cockcroft-Gault is not indexed to body surface area and reflects absolute (not normalized) kidney function.

When to Use Cockcroft-Gault CrCl

Use Cockcroft-Gault CrCl when medication package inserts specify dose adjustments based on creatinine clearance. Many drugs were studied using CrCl (not eGFR) in their pharmacokinetic trials, so the dosing thresholds in their labeling correspond to CrCl values. Common examples include DOACs (apixaban, rivaroxaban, dabigatran, edoxaban), antibiotics (vancomycin, aminoglycosides), and antivirals. Always check the specific drug's labeling for which renal metric is recommended.

Interpreting CrCl Results

General dosing categories: CrCl ≥60 mL/min (mild or no impairment — usually no dose adjustment), 30–59 mL/min (moderate impairment — many drugs require dose reduction), <30 mL/min (severe — many contraindications or significant reductions), <15 mL/min (kidney failure range). These cutoffs vary by drug.

🔑 Klinische Hinweise

Cockcroft-Gault uses actual body weight. In obese patients, using actual weight overestimates CrCl. Some practitioners use adjusted body weight or lean body weight, but no single approach is universally accepted.
CrCl from Cockcroft-Gault overestimates true GFR because creatinine is both filtered and secreted by renal tubules. This overestimation is greater in advanced CKD.
In AKI, serum creatinine is not at steady state, making both eGFR and CrCl unreliable. Clinical judgment and therapeutic drug monitoring are essential.
For the 2021 CKD-EPI equation (eGFR), see the separate eGFR calculator. eGFR and CrCl are not interchangeable for drug dosing purposes.

Schlüsselreferenzen

Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31–41.
Nyman HA, et al. Role of the Cockcroft-Gault equation for estimation of GFR in drug dosing. Clin Pharmacol Ther. 2011;90(1):11–13.
Hudson JQ, Nolin TD. Pragmatic Use of Kidney Function Estimates for Drug Dosing. Clin J Am Soc Nephrol. 2018;13(9):1413–1415.

Formel zuletzt überprüft: Februar 2026