The Creatinine Clearance (CrCl) Calculator estimates kidney function using the Cockcroft-Gault equation to guide safe drug dosing in patients with impaired renal function.
Cockcroft-Gault Formula:
CrCl (mL/min) =
(140 − Age) × Weight (kg) ×
(Sex Factor)
72 × Serum Creatinine
Sex Factor: Male = 1, Female = 0.85
Variables:
- Age: Years.
- Weight: Actual body weight in kilograms (use ideal body weight if obese).
- Sex Factor: 0.85 for females, 1.0 for males.
- Serum Creatinine (SCr): In mg/dL (convert µmol/L → mg/dL by dividing by 88.4).
🧮 Creatinine Clearance Calculator (CrCl)
📐 Formula:
CrCl (mL/min) =
(140 − Age) × Weight (kg) ×
(Sex Factor)
72 × Serum Creatinine
Sex Factor: Male = 1, Female = 0.85
🖊️ Enter the Values:
How to Use the Calculator
Input:
- Age (years).
- Weight (kg).
- Sex (male/female).
- Serum creatinine (mg/dL or µmol/L).
Calculate:
CrCl (mL/min) =
(140 − Age) × Weight (kg) ×
(Sex Factor)
72 × Serum Creatinine
Sex Factor: Male = 1, Female = 0.85
Example Calculation
Patient Data:
- Age = 60 years
- Weight = 70 kg
- Sex = Female
- SCr = 1.0 mg/dL
Calculation:
CrCl (mL/min) =
(140 − Age) × Weight (kg) ×
(Sex Factor)
72 × Serum Creatinine
Sex Factor: Male = 1, Female = 0.85
CrCl (mL/min) =
(140 − 60) × 70 (kg) ×
0.85
72 × 1.0
CrCl (mL/min) =
80 x 70 x 0.85
72
CrCl (mL/min) =
80 x 59.5
72
CrCl (mL/min) =
4,760
72
= 66.11 mL/min
Normal Ranges
| Group | Normal CrCl |
|---|---|
| Adult Males | 95–145 mL/min |
| Adult Females | 85–125 mL/min |
| Elderly (>65) | Decline by ~1 mL/min/year |
Clinical Interpretation
| CrCl (mL/min) | Kidney Function | Drug Dosing Implications |
|---|---|---|
| >90 | Normal | Standard dosing |
| 50–89 | Mild impairment | Adjust nephrotoxic drugs (e.g., vancomycin) |
| 30–49 | Moderate impairment | Reduce doses (e.g., antibiotics, NSAIDs) |
| 15–29 | Severe impairment | Avoid nephrotoxic drugs |
| <15 | Kidney failure | Dialysis required |
Key Notes
- Weight Adjustments:
- Use ideal body weight (IBW) if obese:
- Male IBW = 50 kg + 2.3 kg per inch over 5 feet.
- Female IBW = 45.5 kg + 2.3 kg per inch over 5 feet.
- Limitations:
- Less accurate in extremes (elderly, amputees, muscle wasting).
- Not valid for acute kidney injury (AKI).
CrCl vs. eGFR
| Parameter | CrCl (Cockcroft-Gault) | eGFR (CKD-EPI) |
|---|---|---|
| Purpose | Drug dosing adjustments | CKD staging |
| Accuracy | Reflects tubular secretion | More precise for GFR <60 |
Quick Reference
| Drug | Dose Adjustment if CrCl <50 mL/min |
|---|---|
| Metformin | Contraindicated if CrCl <30 |
| Vancomycin | Increase dosing interval |
| Penicillin | Reduce dose by 25–50% |
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The content on LabTestsGuide.com is for informational and educational purposes only. We do not guarantee the accuracy, completeness, or timeliness of the information provided. Always consult qualified healthcare professionals for medical advice, diagnosis, or treatment. LabTestsGuide.com is not liable for any decisions made based on the information on this site.
