Creatinine Clearance (CrCl) Calculator

This tool uses the Cockcroft-Gault equation, the most widely accepted formula for estimating CrCl. For males:
CrCl = [(140 – age) × weight (kg)] / (72 × SCr)
For females, the result is multiplied by 0.85 (since women typically have lower muscle mass). Users input gender, age, weight (actual, ideal, or adjusted), and serum creatinine (SCr) to get an accurate estimate.

• Actual Body Weight (ABW): Best for non-obese patients.

• Ideal Body Weight (IBW): Used if the patient is underweight or of normal build.

• Adjusted Body Weight (AdjBW): Recommended for obese patients (BMI ≥30) to avoid overestimating CrCl. The formula is:
  AdjBW = IBW + 0.4 × (ABW – IBW)

Men generally have higher muscle mass, producing more creatinine. Since creatinine is a byproduct of muscle metabolism, males tend to have higher baseline CrCl. The calculator adjusts for this by applying a 0.85 multiplier for females to avoid overestimation.

Kidney function naturally declines with age. The Cockcroft-Gault equation accounts for this by subtracting age from 140 (for males). Older patients typically have lower CrCl values, even with normal serum creatinine levels.

• High SCr: May indicate kidney dysfunction, dehydration, or high muscle mass.

• Low SCr: Could suggest low muscle mass (e.g., elderly, malnutrition).
  The calculator adjusts for these factors but consult a doctor for abnormal results.

Patients with chronic kidney disease (CKD), diabetes, or hypertension should monitor CrCl regularly. Those on nephrotoxic drugs (e.g., vancomycin, NSAIDs) may need frequent checks to prevent toxicity.

• >90 mL/min: Normal

• 60-89 mL/min: Mild reduction

• 30-59 mL/min: Moderate CKD

• <30 mL/min: Severe CKD (may need dialysis)

IBW is calculated using the Devine formula:

• Men: 50 kg + 2.3 kg per inch over 5 feet

• Women: 45.5 kg + 2.3 kg per inch over 5 feet
  Height ensures weight estimates align with body frame size.

Yes. A CrCl <15 mL/min often indicates end-stage renal disease (ESRD), requiring dialysis. However, doctors also consider symptoms (e.g., fluid overload, electrolyte imbalances).

Some drugs (e.g., trimethoprim, cimetidine) artificially raise SCr without harming kidneys. Others (e.g., NSAIDs, contrast dye) can worsen kidney function. Always inform your doctor of all medications.

• CrCl: Estimates kidney filtration based on creatinine.

• eGFR: Uses cystatin C or creatinine and is standardized across labs.
  eGFR is now more common, but CrCl remains crucial for drug dosing.

• Stay hydrated (helps flush toxins).

• Control blood pressure & diabetes (major CKD causes).

• Avoid nephrotoxic drugs (e.g., ibuprofen long-term).

• Eat a kidney-friendly diet (low sodium, moderate protein).