Creatinine clearance values are typically interpreted as follows:
The Cockcroft-Gault formula estimates creatinine clearance as a clinical approximation of glomerular filtration rate (GFR). However, creatinine clearance may overestimate GFR by 10-20% and has been replaced in clinical practice by formulas that estimate GFR more directly.
Additionally, the Cockcroft-Gault formula uses weight, which may be less accurate at weight extremes (underweight and especially overweight/obese). Adjustments and estimations are recommended as follows, according to Brown et al. and Winter et al.:
| Category | BMI | Calculation |
|---|---|---|
| Underweight | BMI <18.5 | Calculate using actual/total body weight (i.e., no adjustment) |
| Normal weight | BMI 18.5-24.9 | Calculate using ideal body weight, range using actual weight |
| Overweight/Obese | BMI ≥25 | Calculate using adjusted body weight, range using ideal body weight |
Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. PubMed PMID: 1244564.
Creatinine clearance is an important indicator for assessing kidney function. It estimates how effectively your kidneys can filter creatinine from the blood.
The Cockcroft-Gault formula uses age, weight, gender, and serum creatinine levels to estimate creatinine clearance, while other methods may use different parameters.
You can use this calculator when you need to assess kidney function or monitor changes in kidney function.
The results show your creatinine clearance rate, usually in milliliters per minute (ml/min). Lower values may indicate decreased kidney function.
While the Cockcroft-Gault formula is widely used, it may not be as accurate as other methods in certain situations, especially at weight extremes.
Choose the appropriate weight type based on your BMI. Use actual weight for underweight, ideal weight for normal weight, and adjusted weight for overweight/obese.
This calculator is primarily designed for adults; assessing creatinine clearance in children may require different methods.
This calculator is provided for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
The results from this calculator should be interpreted by healthcare professionals in the context of the patient's overall clinical picture. Decisions about patient care should not be based solely on the results of this calculator.