GFR Calculator
Adjust the inputs below. Results update as you type.
How it works
eGFR estimates kidney filtration capacity. CKD-EPI (2021, race-free): uses creatinine, age, and sex. Stages: ≥90 normal, 60–89 mildly reduced, 30–59 moderately reduced, 15–29 severely reduced, <15 kidney failure. A single low value may reflect dehydration or lab error—trends over time are more informative. Always interpret with a nephrologist.
Input guidance
- Use measured values (recent weight, height, activity level) rather than guesses.
- Recalculate every few weeks as your routine and body metrics change.
- Pair screening metrics with context such as sleep, stress, and medical history.
The formula
Estimated GFR uses equations like CKD-EPI based on serum creatinine, age, and sex to estimate how many milliliters of blood the kidneys filter per minute per 1.73 m².
Worked example
A normal eGFR is about 90 or above. A result of 60 over three months or lower may indicate reduced kidney function and warrants medical review.
More examples to test
- Maintenance case: keep activity constant and observe expected baseline ranges.
- Adjustment case: change only one major variable to understand sensitivity.
How to interpret results
Use results for awareness and planning, then validate with qualified medical or nutrition professionals for individualized decisions.
When this can be inaccurate
Population formulas cannot account for all biological factors such as medical conditions, medication effects, body composition differences, and genetics.
Sources
- National Kidney Foundation — CKD-EPI equation
- Inker et al. (2021) — New creatinine- and cystatin C–based equations
Change history
- July 2026: Quality-reviewed for publication with formula checks and explanatory copy updates.
Site-wide corrections also appear on the corrections log.
Track fitness goals with a top app
General wellness resource.
Frequently asked questions
What is GFR?+
Glomerular filtration rate — a measure of how well the kidneys filter waste from blood. It is a key indicator of kidney health.
What is a normal GFR?+
Roughly 90 or higher in healthy adults. Lower sustained values can signal chronic kidney disease and are staged by severity.
Is this a medical diagnosis?+
No. eGFR is an estimate that supports clinical assessment. Only a healthcare professional can interpret it alongside your full health picture.
Can this calculator diagnose a condition?+
No. It is a screening and education tool only, not a clinical diagnosis.
When should I seek professional advice?+
Seek professional advice when results are extreme, persistent, or conflict with symptoms, goals, or prior medical guidance.