eGFR Calculator
Estimate kidney function from serum creatinine, age, and sex using the race-free CKD-EPI 2021 equation.
Uses the race-free CKD-EPI 2021 creatinine equation for adults (18+). For patients under 18, use a pediatric eGFR calculator instead.
Mildly decreased kidney function
Not a diagnosis. This estimate is for informational and educational purposes only. Kidney function assessment depends on trends over time, urine tests, and clinical context that only a healthcare provider can evaluate. Always discuss results with a doctor.
How eGFR is calculated
CKD stages by eGFR
| Stage | eGFR range | Description |
|---|---|---|
| G1 | ≥ 90 | Normal or high |
| G2 | 60–89 | Mildly decreased |
| G3a | 45–59 | Mildly to moderately decreased |
| G3b | 30–44 | Moderately to severely decreased |
| G4 | 15–29 | Severely decreased |
| G5 | < 15 | Kidney failure |
In the absence of other markers of kidney damage, stages G1 and G2 alone do not meet the criteria for chronic kidney disease.
Common questions
Glomerular filtration rate (GFR) measures how well the kidneys filter waste from the blood, and is considered the best overall indicator of kidney function. Because directly measuring GFR is impractical in routine care, clinicians estimate it (eGFR) from a blood test for serum creatinine, along with age and sex.