This free eGFR calculator estimates how well your kidneys filter blood, using your creatinine blood test, age and sex. It uses the race-free CKD-EPI 2021 equation recommended by the National Kidney Foundation, shows your KDIGO kidney stage, and, if you add your urine albumin result, your combined KDIGO risk.
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What is eGFR?
eGFR stands for estimated glomerular filtration rate: roughly how many milliliters of blood your kidneys clean each minute, scaled to an average body size (mL/min/1.73 m²). It is estimated from creatinine, a waste product from muscle. Higher is better.
eGFR chart: kidney function stages
| Stage (KDIGO) | eGFR | What it means |
|---|---|---|
| G1 | 90 or higher | Normal or high |
| G2 | 60 to 89 | Mildly decreased |
| G3a | 45 to 59 | Mildly to moderately decreased |
| G3b | 30 to 44 | Moderately to severely decreased |
| G4 | 15 to 29 | Severely decreased |
| G5 | under 15 | Kidney failure range |
Chronic kidney disease means an eGFR under 60, or signs of kidney damage such as albumin in the urine, lasting more than 3 months. An eGFR of 60 to 89 alone, without other signs, is not kidney disease and is common with age.
Why urine albumin matters too
| Albumin stage | Urine albumin-to-creatinine ratio |
|---|---|
| A1 | under 30 mg/g (under 3 mg/mmol) |
| A2 | 30 to 300 mg/g (3 to 30 mg/mmol) |
| A3 | over 300 mg/g (over 30 mg/mmol) |
Kidney damage often shows up in the urine before eGFR falls. KDIGO combines both numbers into a risk level. Adults with diabetes or high blood pressure should have both tests regularly.
How the eGFR calculator works
The CKD-EPI 2021 equation was developed without a race term, which earlier versions used. It is the equation most US labs now report. It is designed for adults and for standardized creatinine tests. If your result does not fit the picture, for example because you are very muscular, very frail or take creatine, your doctor can confirm it with a cystatin C test.
When to see a kidney specialist
- eGFR under 30 on repeat testing
- Urine albumin of 300 mg/g (30 mg/mmol) or more on repeat testing
- A fast drop in eGFR, or blood in the urine without an explanation
Kidney function is part of your heart risk too: the AHA PREVENT equations include eGFR. Check your 10-year risk with our heart risk calculator.
eGFR calculator FAQ
What is a normal eGFR for my age?
An eGFR of 90 or more is normal at any age. eGFR tends to fall slowly with age, and values of 60 to 89 are common after 60. They are not a disease unless there are other signs of kidney damage.
Can creatine supplements change my eGFR?
Yes. Creatine, a large meat meal or intense exercise before the test can raise creatinine and make eGFR look lower than it is. Tell your doctor if you use creatine.
Does one low eGFR mean I have kidney disease?
No. Kidney disease needs abnormal results for more than 3 months. Your doctor will usually repeat the test and add a urine albumin test.
Why is race no longer used?
In 2021 the NKF and the American Society of Nephrology recommended the race-free CKD-EPI 2021 equation, which this calculator uses.
This calculator is for education, not diagnosis, and does not replace advice from your doctor. Last reviewed: October 28, 2026. See our medical disclaimer.
