Printed on 2/13/2026
For informational purposes only. This is not medical advice.
Estimated glomerular filtration rate (eGFR) is the best overall measure of kidney function. This calculator uses the CKD-EPI 2021 race-free equation, which estimates how well your kidneys filter waste from the blood based on serum creatinine level, age, and sex. The result is used to stage chronic kidney disease (CKD) from G1 (normal) to G5 (kidney failure).
Formula: CKD-EPI 2021: 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^-1.200 × 0.9938^Age × (1.012 if female)
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
eGFR (estimated glomerular filtration rate) measures how well your kidneys filter waste from the blood. It is expressed in mL/min/1.73m² and is the primary metric used to diagnose and stage chronic kidney disease. A normal eGFR is 90 or above.
The CKD-EPI 2021 equation is the latest race-free version of the Chronic Kidney Disease Epidemiology Collaboration formula. It replaced the 2009 version that included a race coefficient, following recommendations from a joint task force. It uses serum creatinine, age, and sex to estimate GFR.
CKD stages range from G1 (normal, eGFR ≥ 90) to G5 (kidney failure, eGFR < 15). G1-G2 often have no symptoms. G3a (45–59) and G3b (30–44) indicate moderate loss. G4 (15–29) is severe loss. G5 may require dialysis or transplant. Early detection allows treatment to slow progression.
For healthy adults, eGFR is typically checked as part of routine blood work every 1–2 years. For those with diabetes, hypertension, or known CKD, testing frequency increases — often every 3–6 months depending on the stage and rate of decline.