Glomerular Filtration Rate Calculator
Estimate your glomerular filtration rate (eGFR) — a measure of kidney function — using the 2021 CKD-EPI equation.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
This tool provides general educational estimates only and is not medical advice. It does not diagnose, treat, or replace guidance from a qualified healthcare provider. Consult a doctor for decisions about your health.
About the Glomerular Filtration Rate Calculator
The GFR calculator estimates glomerular filtration rate — how many millilitres of blood your kidneys filter per minute, adjusted to a standard body surface area of 1.73 m². It uses the 2021 CKD-EPI creatinine equation, which no longer includes a race coefficient and is recommended by the U.S. National Kidney Foundation and the American Society of Nephrology. You need your age, sex and a serum creatinine value from a blood test. The tool maps the result to the chronic kidney disease stages G1 to G5. A single reading cannot diagnose kidney disease; results must be interpreted by a doctor.
How to use it
- 1Select your sex.
- 2Enter your age in years.
- 3Enter serum creatinine in mg/dL as shown on your lab report (divide µmol/L by 88.4 to convert).
- 4Press Calculate to see your eGFR and the corresponding stage.
Worked example
a 45-year-old man with a serum creatinine of 0.9 mg/dL has an eGFR of about 107 mL/min/1.73 m² (stage G1). A 45-year-old woman with the same creatinine has an eGFR of about 80 (stage G2).
How it works
How it works
eGFR is estimated from serum creatinine, age and sex using the race-free 2021 CKD-EPI formula, and mapped to a CKD stage (G1–G5).
Who it is for
Patients reviewing lab results with their doctor and students learning how eGFR is calculated.
Why it helps
Creatinine alone is hard to interpret; eGFR adjusts it for age and sex.
Common use cases
- Understanding an eGFR figure on a lab report
- Seeing how age changes the estimate for the same creatinine
- Learning the CKD staging system
Frequently asked questions
A:Above 90 mL/min/1.73m² is generally normal; below 60 for 3+ months suggests chronic kidney disease.
A:No. eGFR estimates function; diagnosis needs a clinician and further tests.
Reviewed for accuracy · Last updated October 7, 2026
Formulas follow recognised clinical references — including WHO BMI classifications, the Mifflin-St Jeor equation, and Naegele’s rule — and are periodically checked against published reference values.
CalcWisee Editorial Team
Calculator development and formula review
CalcWisee is an independent site founded by Ayman. Every calculator is built from a published formula or official definition, tested against hand-worked examples before it goes live, and corrected promptly when a reader reports an issue to ayman@calcwisee.com.
Expertise: Financial mathematics, Health and fitness formulas, Applied mathematics, Unit conversion standards
References & sources
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