eGFR Calculator
Estimate your kidney function (eGFR) from your serum creatinine, age and sex.
What is eGFR?
Your estimated glomerular filtration rate (eGFR) is a number that reflects how well your kidneys are filtering waste from your blood. It is not measured directly. Instead, it is calculated from your serum creatinine together with your age and sex.
Creatinine is a waste product from normal muscle activity. Healthy kidneys clear it steadily, so when filtration drops, creatinine rises. Because the same creatinine value means different things at different ages and between men and women, eGFR is usually a more useful way to read kidney function than creatinine alone.
How this calculator works
This tool uses the 2021 CKD-EPI creatinine equation, the current international standard. It is "race-free": unlike older formulas, it does not use a race coefficient. It is validated for adults aged 18 and over, so this calculator is limited to adults. eGFR in children is estimated with a different equation.
You can enter creatinine in mg/dL (the unit most Indian labs report) or in micromoles per litre (µmol/L) using the unit toggle. Everything is calculated in your browser, and nothing you enter is sent anywhere or stored.
What your result means
eGFR is reported in mL/min/1.73 m² and grouped into stages defined by KDIGO, the global kidney guideline body:
| Stage | eGFR | What it means |
|---|---|---|
| G1 | 90 or above | Normal or high filtration |
| G2 | 60 to 89 | Mildly decreased (often normal for older adults) |
| G3a | 45 to 59 | Mildly to moderately decreased |
| G3b | 30 to 44 | Moderately to severely decreased |
| G4 | 15 to 29 | Severely decreased |
| G5 | below 15 | Kidney failure |
A stage on its own is not a diagnosis. Chronic kidney disease is defined by reduced filtration or signs of kidney damage that persist for at least three months, so a single reading is only a snapshot.
Limitations to keep in mind
eGFR is an estimate. It can be misleading if your muscle mass is very high or very low, during pregnancy, with some medications, or if your kidney function is changing quickly (for example during an acute illness). It should always be read alongside other results, such as a urine albumin test, and interpreted by your doctor.
Frequently asked questions
What is a normal eGFR?
An eGFR of 90 or above, with no other signs of kidney damage, is generally considered normal. Values decline gradually with age, so a mildly reduced eGFR in an older adult is not always a sign of disease.
Is eGFR the same as creatinine?
No. Creatinine is the raw blood measurement. eGFR is an estimate calculated from your creatinine, age and sex that reflects how well your kidneys filter. The same creatinine can give different eGFR values depending on age and sex.
Why does this calculator ask for sex but not race?
It uses the 2021 CKD-EPI creatinine equation, which removed the race coefficient used in older formulas. Sex and age are still needed because they affect the relationship between creatinine and filtration.
Can I use this for a child?
No. This equation is validated for adults aged 18 and over. eGFR in children is estimated with a different formula (the Bedside Schwartz equation), so this tool is limited to adults.
My eGFR is slightly low. Should I worry?
A single mildly reduced eGFR is common and is not a diagnosis on its own. Kidney function is assessed over time and alongside other tests such as urine albumin. Share the result with your doctor, who can interpret it in context.
Formula source: Inker LA et al. New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race. N Engl J Med 2021;385:1737-1749.
Related reading
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