Creatinine Clearance Calculator

Written by Great Medico

Updated September 24, 2026 •2 min read

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In nephrology and urology, the same number can mean different things in acute illness, chronic disease, or imaging follow-up. Creatinine Clearance Calculator handles the arithmetic while the clinical setting supplies the meaning.

What this calculator does

Creatinine Clearance Calculator uses Age, Sex, Weight, Height, Serum creatinine, Urine creatinine, Urine volume, and Collection time to calculate creatinine clearance. It is built around the exact fields displayed in this plugin rather than a generic version of the topic. Where supported, it also shows BMI, Weight used, and Direct measured CrCl so the primary result is easier to place in context. Kidney calculations often depend on paired laboratory samples, stable physiology, and the population in which the equation was validated. Acute changes in kidney function or nonstandard sampling can make an apparently precise number unreliable.

How to use it

Complete the requested fields, including Age, Sex, Weight, Height, Serum creatinine, and Urine creatinine, then finish the remaining items shown in the calculator. Confirm that each yes/no, category, date, or score option is applied exactly as labeled. For paired blood, urine, or dialysis measurements, use samples and treatment data from the same collection or clinical episode when the formula requires it.

How the calculation works

Cockcroft–Gault creatinine clearance is calculated from age, serum creatinine, sex, and a dosing weight. This implementation derives BMI and then selects actual, ideal, or adjusted weight according to its built-in BMI rules before applying [(140 − age) × weight] / (72 × creatinine), multiplied by 0.85 for females. If urine creatinine, urine volume, and collection time are entered, it also reports a direct measured clearance from urine creatinine × urine flow / serum creatinine.

Example

Using the sample values prefilled in this calculator, the primary result is 78.56 mL/min (Cockcroft–Gault creatinine clearance), BMI is 24.5, and Weight used is 70.7 kg. This worked example shows how the plugin’s own default inputs flow through the implemented method; replace them with the correct patient, laboratory, imaging, or personal values before interpreting a result.

How to interpret the result

Interpret the output as cockcroft–gault creatinine clearance from the formula implemented here. Compare it with the relevant laboratory, imaging, pathology, or treatment context, and use trends or a validated clinical pathway when appropriate. One calculated value by itself cannot establish the cause of a urologic or kidney problem or predict an individual outcome.

Limitations and notes

Cockcroft–Gault was developed with older creatinine methods and is not interchangeable with modern eGFR. Drug labels may specify particular weight and creatinine conventions, and very low muscle mass, obesity, pregnancy, unstable kidney function, and rapidly changing creatinine can make estimates unreliable. Timed urine clearance also depends on complete collection.