GFR National Kidney Calculator

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 the GFR National Kidney Calculator?

The GFR National Kidney Calculator uses the CKD-EPI 2021 equation to estimate glomerular filtration rate (GFR) from serum creatinine, age, and sex. This updated equation provides improved accuracy in assessing kidney function across diverse 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 2021 CKD-EPI equation incorporates updated coefficients based on recent population studies, providing more accurate GFR estimates across different demographic groups.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is essential for early detection of chronic kidney disease, monitoring disease progression, and guiding appropriate treatment decisions and medication adjustments.

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). Use fasting serum creatinine values for optimal accuracy.

5. Frequently Asked Questions (FAQ)

Q1: What's new in the CKD-EPI 2021 equation?
A: The 2021 version uses updated coefficients (142, -1.200, 0.9938, 1.012) based on more recent and diverse population data, improving accuracy across different ethnic groups.

Q2: How does this differ from the original CKD-EPI equation?
A: The 2021 equation has modified coefficients and exponents, with the female multiplier reduced from 1.018 to 1.012, and other parameters optimized for contemporary populations.

Q3: What are the clinical implications of the updated equation?
A: The new equation may reclassify some patients' CKD stages and could affect medication dosing decisions, particularly for drugs with narrow therapeutic windows.

Q4: Is race no longer used in the 2021 equation?
A: The 2021 CKD-EPI equation was developed to be race-neutral, using a single equation that performs well across all racial and ethnic groups without race-specific multipliers.

Q5: When should I use this calculator versus other GFR equations?
A: The CKD-EPI 2021 equation is recommended for most adult patients as it provides the most current and accurate GFR estimation based on contemporary population data.