eGFR National Kidney Foundation Calculator

EGFR National Kidney Foundation Calculator

NKF 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 NKF CKD-EPI 2021 Equation?

The NKF CKD-EPI 2021 equation is the latest formula developed by the National Kidney Foundation for estimating 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 NKF 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: This updated equation incorporates refined coefficients based on recent population studies, providing more accurate GFR estimates without race adjustment.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is essential for early detection of chronic kidney disease, monitoring disease progression, and guiding appropriate clinical management and medication dosing.

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 NKF CKD-EPI 2021 equation?
A: The 2021 version uses updated coefficients and removes race adjustment, providing more equitable and accurate GFR estimates across all populations.

Q2: How does this differ from previous CKD-EPI equations?
A: This version features refined mathematical coefficients and eliminates race-based multipliers, aligning with current understanding of kidney function across diverse populations.

Q3: What are the clinical applications of this calculator?
A: Used for CKD screening, staging, monitoring disease progression, and adjusting medication doses in patients with impaired kidney function.

Q4: Are there limitations to this equation?
A: May be less accurate in extremes of age, body composition, amputees, pregnant women, and those with rapidly changing kidney function or muscle mass.

Q5: When should confirmatory testing be considered?
A: For critical decisions like kidney donation evaluation or precise drug dosing, measured GFR (e.g., iohexol clearance) may be necessary.