NIDDK Calculator GFR

NIDDK GFR Calculator using CKD-EPI 2021:

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

Estimated GFR (eGFR):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the NIDDK GFR Calculator?

The NIDDK (National Institute of Diabetes and Digestive and Kidney Diseases) GFR 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 NIDDK 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 equation incorporates updated coefficients from the 2021 CKD-EPI study, providing more accurate GFR estimation across different demographic groups.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is essential for diagnosing chronic kidney disease, monitoring disease progression, determining appropriate treatment strategies, and guiding medication dosing decisions.

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

Q2: How does this differ from previous CKD-EPI equations?
A: This version uses refined coefficients (142, -1.200, 0.9938) and gender-specific alpha values for improved accuracy.

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

Q4: Are there population limitations?
A: May be less accurate in extremes of age, pregnancy, severe malnutrition, amputees, and those with rapidly changing kidney function.

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 recommended.