How do I calculate creatinine clearance?

You need age, sex, body weight and blood creatinine. The calculator puts them into the Cockcroft–Gault formula and returns clearance in mL / min. Enter creatinine in µmol / L — conversion to mg / dL (÷88.4) is automatic.

How is Cockcroft–Gault clearance different from eGFR?

Cockcroft–Gault clearance is used for drug dose adjustment (labels are calibrated to it). eGFR by CKD-EPI is for staging chronic kidney disease. They are different tasks, so values may differ. For a CKD stage, use the separate eGFR calculator.

Which body weight should I use?

By default, actual weight. But in obesity it overestimates clearance, so when you enter your height the calculator uses ideal (Devine) or adjusted body weight. This is the standard clinical approach to dosing.

What clearance is normal?

In healthy adults it is usually 90 mL / min and above. 60–89 is a mild decrease. Below 60, and especially below 30, calls for careful dosing of kidney-cleared drugs and a doctor’s advice.

Can I use it in acute kidney injury?

No. The formula assumes a stable creatinine. If it is changing rapidly (acute injury), Cockcroft–Gault clearance is inaccurate — the doctor follows the creatinine trend, not a single value.

Creatinine clearance calculator (Cockcroft–Gault)

Enter age, sex, body weight and blood creatinine — the calculator computes creatinine clearance with the Cockcroft–Gault formula. This value is historically used to adjust doses of drugs cleared by the kidneys. Enter your height and it accounts for ideal body weight — more accurate in people with excess weight. Creatinine is in µmol / L, as on lab reports in many countries.

Calculate creatinine clearance

Enter creatinine, age, sex and body weight — the result appears instantly.

Creatinine clearance: functional zones

A guide by clearance (mL / min). For drug dosing, package inserts often use 50 and 30 mL / min thresholds. This is not a CKD stage — that is set by eGFR (CKD-EPI) over time.

Clearance, mL / min	Kidney function
90 and above	Normal
60–89	Mildly decreased
30–59	Moderately decreased
15–29	Severely decreased
below 15	Kidney failure

What creatinine clearance is

Creatinine clearance is the volume of blood plasma the kidneys fully clear of creatinine per minute. The worse the kidneys work, the lower the clearance. The Cockcroft–Gault formula estimates it from age, sex, body weight and creatinine — without a 24-hour urine collection.

Its main use is adjusting doses of kidney-cleared drugs: many drug labels are historically calibrated to Cockcroft–Gault clearance rather than to eGFR.

The Cockcroft–Gault formula

Clearance = (140 − age) × weight(kg) × k / (72 × creatinine[mg / dL]), where k = 0.85 for women and 1 for men. Creatinine measured in µmol / L is converted to mg / dL automatically (divided by 88.4).

The formula assumes an adult with stable kidney function. With a rapidly changing creatinine (acute injury) it is inaccurate — then the trend, not a single value, is used.

Clearance (Cockcroft–Gault) vs eGFR (CKD-EPI)

These are two different tools. Cockcroft–Gault clearance is for drug dosing: that is how labels are written and how it is done in hospital. eGFR by CKD-EPI 2021 is the modern standard for staging chronic kidney disease (stages G1–G5) and is normalised to 1.73 m² of body surface.

Their values can differ, especially with atypical body weight — that is fine, because the formulas serve different goals. For a CKD stage use our eGFR calculator; for a drug dose, this one.

Body weight correction

On actual weight the formula overestimates clearance in obesity (fat tissue barely filters). So when you enter your height, the calculator computes ideal body weight (Devine) and, in obesity, uses adjusted body weight — bringing the estimate closer to reality.

For underweight it uses actual weight, for normal weight the ideal. The calculator shows which weight was used and the clearance on actual weight for comparison.

One estimate is not a diagnosis

Clearance is an estimate, not an exact measurement, and does not replace a doctor or clinical pharmacist. The final drug dose is chosen by a doctor considering the whole picture: diagnosis, other tests and medications.

Frequently asked questions

You need age, sex, body weight and blood creatinine. The calculator puts them into the Cockcroft–Gault formula and returns clearance in mL / min. Enter creatinine in µmol / L — conversion to mg / dL (÷88.4) is automatic.
Cockcroft–Gault clearance is used for drug dose adjustment (labels are calibrated to it). eGFR by CKD-EPI is for staging chronic kidney disease. They are different tasks, so values may differ. For a CKD stage, use the separate eGFR calculator.
By default, actual weight. But in obesity it overestimates clearance, so when you enter your height the calculator uses ideal (Devine) or adjusted body weight. This is the standard clinical approach to dosing.
In healthy adults it is usually 90 mL / min and above. 60–89 is a mild decrease. Below 60, and especially below 30, calls for careful dosing of kidney-cleared drugs and a doctor’s advice.
No. The formula assumes a stable creatinine. If it is changing rapidly (acute injury), Cockcroft–Gault clearance is inaccurate — the doctor follows the creatinine trend, not a single value.

Creatinine is a value from your blood test

Upload your report — AI reads creatinine, urea and eGFR together, links them to other values and explains what to do.

Decode my lab results

This calculator is for reference and information only and is not a diagnosis. Drug doses and kidney-function assessment are determined by a doctor.