eGFR Calculator Formula

eGFR Formula:

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

Estimated GFR (eGFR):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the eGFR Calculator Formula?

The eGFR (estimated Glomerular Filtration Rate) formula calculates kidney function based on serum creatinine, age, and gender. This specific formula provides an accurate assessment of glomerular filtration rate using mathematical coefficients optimized for different demographic groups.

2. How Does the Calculator Work?

The calculator uses the eGFR formula:

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

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: The equation models the non-linear relationship between serum creatinine and glomerular filtration rate, with gender-specific coefficients to improve accuracy across different populations.

3. Importance of eGFR Calculation

Details: Accurate eGFR calculation is essential for assessing kidney function, detecting early-stage chronic kidney disease, monitoring disease progression, and adjusting medication dosages for renal clearance.

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 clinical significance of eGFR?
A: eGFR provides a standardized measure of kidney function that helps in diagnosing and staging chronic kidney disease, guiding treatment decisions, and predicting renal outcomes.

Q2: What are the reference ranges for eGFR?
A: Normal eGFR is typically ≥90 mL/min/1.73m². Values between 60-89 may indicate mild reduction, while values below 60 for 3+ months suggest chronic kidney disease.

Q3: How does age affect eGFR calculation?
A: The formula includes an age factor (0.9938^age) that accounts for the natural decline in kidney function with advancing age.

Q4: Why are there different coefficients for males and females?
A: Gender-specific coefficients account for differences in muscle mass and creatinine production between males and females, providing more accurate GFR estimates.

Q5: When should this formula not be used?
A: This formula may be less accurate in extreme age groups, pregnant women, individuals with amputations, severe malnutrition, or rapidly changing kidney function.