GFR Calculator
Enter Measurements
Results (Kidney Function)
| eGFR (2021 CKD-EPI) | — |
|---|---|
| Kidney Function Stage | — |
| Cockcroft-Gault GFR | — |
Understanding GFR & Kidney Function
Glomerular Filtration Rate (GFR) measures how well the kidneys filter waste products from the blood. Since direct measurement is complex, clinicians use equations to calculate estimated GFR (eGFR) based on serum creatinine, age, and sex.
CKD Kidney Stages
The National Kidney Foundation classifies chronic kidney disease (CKD) stages using eGFR values (expressed in $\text{mL/min/1.73 m}^2$):
- **Stage 1:** $\ge 90$ — Normal or high kidney function with evidence of kidney damage.
- **Stage 2:** $60 - 89$ — Mildly decreased kidney function.
- **Stage 3a:** $45 - 59$ — Mildly to moderately decreased.
- **Stage 3b:** $30 - 44$ — Moderately to severely decreased.
- **Stage 4:** $15 - 29$ — Severely decreased kidney function.
- **Stage 5:** $< 15$ — Kidney failure (uremia or dialysis indicator).
Equations
- **CKD-EPI (2021):** The current recommended race-free standard equation. - **Cockcroft-Gault:** An older equation widely used for drug dosage calculations because it incorporates body weight.
Disclaimer. This calculator is informational only and is not a substitute for clinical diagnosis, medical advice, or expert evaluation. GFR estimations are less accurate in cases of extreme muscle mass, pregnancy, acute kidney injury, or unstable health. Consult a nephrologist or healthcare professional for renal concerns.