eGFR Calculator — Estimate Your Kidney Function (GFR)
Calculate your eGFR (Estimated Glomerular Filtration Rate) online using the modern CKD-EPI 2021 equation based on serum creatinine, age, and sex.
Understanding the eGFR Calculator
Glomerular Filtration Rate (GFR) represents the flow rate of filtered fluid through the kidneys. It is the clinical gold standard for measuring kidney function. Because direct measurement of GFR is complex and invasive, clinicians use equations to estimate GFR (eGFR) from the level of creatinine in your blood.
The CKD-EPI 2021 Equation
This calculator utilizes the 2021 CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation. This modern equation was developed to estimate GFR without using a race-based coefficient, which was used in older equations like MDRD. Research shows the 2021 equation provides high clinical accuracy and patient equity.
Interpreting Kidney Staging
GFR values are categorized into stages to guide clinical decision making:
- Stage G1 (eGFR ≥ 90): Normal or high kidney function.
- Stage G2 (eGFR 60–89): Mildly decreased kidney function.
- Stage G3a (eGFR 45–59): Mildly to moderately decreased kidney function.
- Stage G3b (eGFR 30–44): Moderately to severely decreased kidney function.
- Stage G4 (eGFR 15–29): Severely decreased kidney function.
- Stage G5 (eGFR < 15): Kidney failure.