What Is eGFR Calculation

CKD-EPI 2021 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 eGFR Calculation?

The eGFR (estimated Glomerular Filtration Rate) calculation using the CKD-EPI 2021 equation estimates kidney function from serum creatinine, age, and sex. This updated equation provides improved accuracy in assessing kidney function across different populations.

2. How Does the Calculator Work?

The calculator uses the CKD-EPI 2021 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: The CKD-EPI 2021 equation represents an update to the original CKD-EPI formula with refined coefficients for better accuracy across diverse populations.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is essential for detecting early kidney disease, monitoring disease progression, and adjusting medication dosages based on kidney 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).

5. Frequently Asked Questions (FAQ)

Q1: What's new in the CKD-EPI 2021 equation?
A: The 2021 version features updated coefficients (142, -1.200, 0.9938) and refined gender adjustments for improved accuracy across diverse populations.

Q2: How does this compare to the original CKD-EPI equation?
A: The 2021 version provides more consistent performance across different age groups and ethnicities while maintaining accuracy at higher GFR levels.

Q3: What are the clinical applications of eGFR?
A: eGFR is used for CKD screening, staging kidney disease, drug dosing adjustments, and monitoring kidney function over time.

Q4: Are there population limitations?
A: The equation may be less accurate in extreme age groups, pregnant women, and individuals with unusual muscle mass or rapidly changing kidney function.

Q5: When should eGFR be interpreted with caution?
A: Caution is advised in hospitalized patients, those with acute kidney injury, and individuals with conditions affecting creatinine production.