GFR Calculator (CKD-EPI Formula)

CKD-EPI Equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Estimated GFR (eGFR):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What Is The GFR Calculator (CKD-EPI Formula)?

The GFR Calculator using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formula estimates glomerular filtration rate from serum creatinine, age, and sex. This equation provides an accurate assessment of kidney function for clinical evaluation.

2. How Does The Calculator Work?

The calculator uses the CKD-EPI equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Where:

\( Scr \) — Serum creatinine (mg/dL)
\( \kappa \) — 0.7 (female) or 0.9 (male)
\( \alpha \) — -0.241 (female) or -0.302 (male)
\( age \) — Age in years
1.012 — Female multiplier

Explanation: This equation models the non-linear relationship between serum creatinine and glomerular filtration rate, with gender-specific coefficients for improved accuracy.

3. Importance Of eGFR Calculation

Details: Glomerular filtration rate estimation is essential for detecting kidney dysfunction, staging chronic kidney disease, and adjusting medication dosages based on renal function.

4. Using The Calculator

Tips: Enter serum creatinine in mg/dL, age in years, and select gender. Ensure all values are valid (creatinine > 0, age between 1-120 years) for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What Is The Difference Between This And Other GFR Equations?
A: This CKD-EPI formula uses updated coefficients (142, -1.200, 0.9938) and gender-specific parameters for enhanced accuracy across different population groups.

Q2: What Are Normal eGFR Values?
A: Normal glomerular filtration rate is typically ≥90 mL/min/1.73m², with expected decline due to aging. Values below 60 mL/min/1.73m² may indicate chronic kidney disease.

Q3: When Should Serum Creatinine Be Measured?
A: Morning fasting samples are preferred, though random samples are acceptable. Avoid testing after high-protein meals or intense physical activity.

Q4: Are There Limitations To This Equation?
A: Accuracy may be reduced in extreme age groups, pregnant women, individuals with muscle mass abnormalities, or those with rapidly changing renal function.

Q5: Can This Calculator Be Used For Drug Dosing?
A: While useful for estimation, precise drug dosing may require measured GFR in specific clinical situations or high-risk populations.