Creatinine Clearance Calculator

Creatinine Clearance Calculator for Nephrology. This is unindexed mL/min, not CKD-EPI eGFR in mL/min/1.73 m2. It does not return a medication dose or diagnose CKD.

Clinical learning case

A clearance estimate is not a medication order

Fictional teaching case. Not an individual treatment recommendation.

For an arithmetic exercise, use age 72 years, weight 60 kg and serum creatinine 1.1 mg/dL for a woman with stable kidney function. A colleague asks whether the resulting Cockcroft-Gault estimate automatically determines an anticoagulant dose.

  1. Subtract age from 140 and multiply by the entered weight: (140 - 72) x 60 = 4,080.
  2. Divide by 72 x 1.1 = 79.2, then apply the equation's female factor: 4,080 / 79.2 x 0.85 = 43.79 mL/min, or approximately 43.8.
  3. Stop at the estimate. Medication selection and dosing require the particular drug, indication, current prescribing information and patient context. There is no universal dose reduction at this number.

Clinical reasoning

Cockcroft-Gault estimates creatinine clearance; it is not the same quantity as body-surface-area-indexed eGFR. NIDDK describes several kidney-function methods used in drug labels. The National Kidney Foundation now supports transition toward race-free eGFR for medication decisions. That evolving practice does not justify silently substituting equations in an individual protocol: identify the specified method and resolve discrepancies with the prescribing team.

Error to avoid

Weight is a direct multiplier. Substituting 80 kg for 60 kg, with every other input unchanged, raises the estimate by one third to about 58.4 mL/min. That is a calculation difference, not evidence that kidney function improved. Document which weight was entered and why; do not try several weights simply to cross a desired dosing threshold.

Can 43.8 mL/min alone establish a CKD stage or an apixaban dose?

Neither. This is an estimated creatinine clearance, not a complete CKD assessment. Apixaban dosing is indication- and label-specific and cannot be inferred from this teaching case. Consult current prescribing information and local pharmacy guidance.

Example documentation

Cockcroft-Gault estimated CrCl 43.8 mL/min; age 72, entered weight 60 kg, creatinine 1.1 mg/dL, female factor 0.85. Weight basis and creatinine stability documented. No medication dose inferred from this result alone.

Sources for this lesson

Source check: 2026-09-07. Editorial content by Quick Medical Calculator. Independent clinical sign-off is not recorded for this lesson.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

Cockcroft-Gault estimated clearance = (140 - age in years) x weight in kg / (72 x serum creatinine in mg/dL), multiplied by 0.85 for the female coefficient. SI creatinine is divided by 88.4. The entered weight is used directly without an automatic ideal-weight substitution.

When to use this calculator

Adult stable-creatinine clearance estimation where Cockcroft-Gault is the specified method, including interpretation alongside a medication label.

Inputs used

  • Age (years)
  • Weight used in equation (kg; US lb)
  • Sex coefficient in the source model
  • Serum creatinine (umol/L; US mg/dL)

Clinical interpretation

This is unindexed mL/min, not CKD-EPI eGFR in mL/min/1.73 m2. It does not return a medication dose or diagnose CKD.

Worked example

Age 72, weight 60 kg, creatinine 1.1 mg/dL and the female coefficient give 43.79 mL/min. The same creatinine is 97.24 umol/L; switching units must preserve the result.

Limitations and safety notes

Weight selection, obesity, edema, unusual muscle mass and unstable creatinine limit accuracy. The new component must be mapped separately from the CKD-EPI calculator; broad alias restoration is not assumed.

Frequently asked questions

Should this replace every laboratory eGFR?

No. These are different estimates with different units and purposes. Use the method required by the clinical question or medication documentation.

What does this result leave unresolved?

Weight selection, obesity, edema, unusual muscle mass and unstable creatinine limit accuracy. The new component must be mapped separately from the CKD-EPI calculator; broad alias restoration is not assumed.

References

  • https://pubmed.ncbi.nlm.nih.gov/1244564/
  • https://pmc.ncbi.nlm.nih.gov/articles/PMC2756662/

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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