Creatinine Clearance Calculator Kidney.Org

Cockcroft-Gault Equation:

\[ CrCl = \frac{(140 - Age) \times Weight \times 0.85 \text{ (if female)}}{72 \times SCr} \]

Age:

years

Weight:

Serum Creatinine (SCr):

mg/dL

Gender:

Creatinine Clearance (CrCl):

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1. What Is The Creatinine Clearance Calculator?

The Creatinine Clearance Calculator uses the Cockcroft-Gault equation to estimate creatinine clearance (CrCl) from serum creatinine, age, weight, and gender. This calculation helps assess kidney function and is commonly used for medication dosing adjustments.

2. How Does The Calculator Work?

The calculator uses the Cockcroft-Gault equation:

\[ CrCl = \frac{(140 - Age) \times Weight \times 0.85 \text{ (if female)}}{72 \times SCr} \]

Where:

\( Age \) — Age in years
\( Weight \) — Body weight in kilograms
\( SCr \) — Serum creatinine in mg/dL
\( 0.85 \) — Female gender multiplier

Explanation: The equation estimates creatinine clearance based on demographic and laboratory values, with adjustment for gender differences in muscle mass.

3. Importance Of Creatinine Clearance Calculation

Details: Creatinine clearance estimation is essential for assessing renal function, determining appropriate drug dosages for renally excreted medications, and monitoring kidney disease progression.

4. Using The Calculator

Tips: Enter age in years, weight in kilograms, serum creatinine in mg/dL, and select gender. All values must be valid (age 1-120 years, weight > 0 kg, creatinine > 0 mg/dL).

5. Frequently Asked Questions (FAQ)

Q1: What Is The Difference Between CrCl And eGFR?
A: CrCl estimates creatinine clearance using Cockcroft-Gault, while eGFR estimates glomerular filtration rate using equations like CKD-EPI. They serve similar purposes but use different calculations.

Q2: When Is Cockcroft-Gault Preferred Over eGFR?
A: Cockcroft-Gault is often preferred for drug dosing decisions, particularly in older medications where dosing guidelines were established using this equation.

Q3: What Are Normal CrCl Values?
A: Normal CrCl is approximately 90-120 mL/min for young adults, decreasing with age. Values below 60 mL/min may indicate impaired kidney function.

Q4: Are There Limitations To This Equation?
A: The equation may overestimate CrCl in obese patients, elderly, those with low muscle mass, or when serum creatinine is not at steady state.

Q5: Should Ideal Body Weight Be Used?
A: For obese patients (BMI > 30), some guidelines recommend using ideal body weight rather than actual body weight in the calculation.