Creatinine Clearance Calculator

What is Creatinine Clearance?

Creatinine clearance is a measurement that estimates how well your kidneys filter waste from your blood. It represents the volume of blood plasma cleared of creatinine per minute and serves as an indicator of glomerular filtration rate (GFR), which is the standard measure of kidney function.

This calculator uses the Cockcroft-Gault equation, developed in 1973, which estimates creatinine clearance based on age, gender, weight, and serum creatinine levels. The formula accounts for the natural decline in kidney function with age and differences between males and females.

How to Use This Calculator

Required Information

• Age: Enter your age in years (1-120)
• Gender: Select male or female from the dropdown
• Weight: Enter your current weight in kilograms
• Serum Creatinine: Enter your most recent creatinine level in μmol/L

Cockcroft-Gault Formula

The calculation uses the following equation:

CrCl = [(140 – Age) × Weight × (0.85 if female)] ÷ (0.814 × Serum Creatinine)

Interpreting Your Results

Normal Function

A creatinine clearance above 90 mL/min typically indicates normal kidney function. Values between 60-89 mL/min may be normal depending on age and other factors, particularly in the absence of other signs of kidney disease.

Mild to Moderate Impairment

Values between 30-59 mL/min suggest moderate kidney impairment. This range often requires monitoring and may need medical intervention to slow progression.

Severe Impairment

Values below 30 mL/min indicate severe kidney impairment. Patients in this range may need preparation for renal replacement therapy and specialist nephrology care.

End-Stage Kidney Disease

Values below 15 mL/min typically indicate end-stage kidney disease, where dialysis or kidney transplantation may be necessary.

Clinical Applications

Drug Dosing

Creatinine clearance is commonly used to adjust medication dosages for drugs that are primarily eliminated by the kidneys. Many pharmaceutical guidelines reference creatinine clearance rather than eGFR for dose adjustments.

Disease Monitoring

Healthcare providers use creatinine clearance to monitor the progression of kidney disease, determine when interventions are needed, and decide when patients should be referred to specialist care.

Treatment Planning

Results help clinicians decide when to initiate treatments such as ACE inhibitors, plan for renal replacement therapy, or adjust follow-up schedules for patients with chronic kidney disease.

Factors Affecting Accuracy

Patient Factors

• Extreme body compositions (very muscular, malnourished, or obese)
• Limb amputations or significant muscle loss
• Pregnancy (normal clearance can reach 200 mL/min)
• Recent changes in kidney function (acute kidney injury)

Laboratory Considerations

• Timing of blood samples (should be processed within 12 hours)
• Recent meat consumption (can temporarily increase creatinine)
• Laboratory assay methods (enzymatic vs colorimetric)
• Hydration status at time of blood draw

When to Consult Healthcare Providers

This calculator is for educational purposes and should not replace professional medical advice. Contact your healthcare provider if:

• Your calculated clearance is below normal ranges
• You have symptoms of kidney disease (swelling, fatigue, changes in urination)
• You’re taking medications that require dose adjustment
• You have diabetes, hypertension, or other conditions affecting kidneys
• Your results show a significant change from previous calculations