eGFR Calculator (CKD-EPI 2021)
By Santaji GadepatilinUpdated October 27, 2026
Estimated glomerular filtration rate (eGFR) measures kidney function from a blood creatinine test, age and sex. It is used to stage chronic kidney disease.
How to use the eGFR calculator
Enter serum creatinine in mg/dL, age and sex. The result is the estimated GFR in mL/min per 1.73 m², with the matching CKD stage.
This tool is for education. Diagnosis and treatment decisions need a clinician, repeated tests and other markers such as urine albumin.
The CKD-EPI 2021 equation
eGFR = 142 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.200 × 0.9938age × 1.012 [female]
| Female | Male | |
|---|---|---|
| κ | 0.7 | 0.9 |
| α | −0.241 | −0.302 |
eGFR by creatinine and age
| Creatinine | Male, 40 | Male, 70 | Female, 40 | Female, 70 |
|---|---|---|---|---|
| 0.6 mg/dL | 125 | 104 | 116 | 97 |
| 0.8 mg/dL | 115 | 95 | 95 | 79 |
| 1.0 mg/dL | 98 | 81 | 73 | 61 |
| 1.2 mg/dL | 78 | 65 | 59 | 49 |
| 1.5 mg/dL | 60 | 50 | 45 | 37 |
| 2.0 mg/dL | 42 | 35 | 32 | 26 |
| 3.0 mg/dL | 26 | 22 | 20 | 16 |
CKD stages (KDIGO)
| Stage | eGFR | 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 | under 15 | Kidney failure |
Chronic kidney disease is diagnosed when eGFR stays below 60 for more than 3 months, or when there are other signs of kidney damage.
When eGFR is less reliable
- Very high or low muscle mass (bodybuilders, amputees, frail elderly).
- Acute kidney injury, when creatinine is changing quickly.
- Pregnancy and children (use paediatric equations).
- High meat intake or creatine supplements shortly before the test.
Cystatin C based equations can help in these situations.
Frequently asked questions
What is a normal eGFR?
90 or above is normal. Values of 60–89 can be normal in older adults if there are no other signs of kidney damage.
Why does the 2021 equation not use race?
The 2021 CKD-EPI equation was refitted without a race coefficient, following recommendations from US kidney organisations, to avoid race-based adjustments.
How do I convert µmol/L to mg/dL?
Divide by 88.4. A creatinine of 88 µmol/L is about 1.0 mg/dL.
Is eGFR the same as creatinine clearance?
No. eGFR is normalised to 1.73 m² of body surface area and is used for CKD staging. Creatinine clearance (Cockcroft–Gault) is often used for drug dosing.