eGFR Calculator (Kidney Function)
Estimate glomerular filtration rate (eGFR) using the CKD-EPI formula to assess kidney function.
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How to use this calculator
The CKD-EPI 2009 equation estimates glomerular filtration rate from serum creatinine, age, sex, and race. κ is 0.7 for females and 0.9 for males; α is −0.329 for females and −0.411 for males. The result is expressed as mL/min per 1.73 m² of body surface area.
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Enter your serum creatinine value in mg/dL from a recent blood test result.
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Enter your age, select your gender and race factor for the CKD-EPI formula.
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Your estimated eGFR and corresponding CKD stage will be calculated instantly.
Frequently asked questions
What is eGFR and what does it measure?
eGFR (estimated Glomerular Filtration Rate) measures how well your kidneys filter waste from the blood, expressed as mL per minute per 1.73 m² of body surface area. A normal eGFR is 90 or above. Values below 60 for more than 3 months indicate chronic kidney disease (CKD). eGFR is calculated from a simple serum creatinine blood test along with age, sex, and race.
Why does the formula include a race factor?
The CKD-EPI 2009 formula includes a race multiplier for Black/African American individuals based on studies showing differences in average serum creatinine levels related to average muscle mass differences at a population level. This is a statistical adjustment in the original formula. Note that the 2021 CKD-EPI revision removed the race variable. This calculator uses the 2009 version which remains widely cited.
What eGFR level should prompt a doctor visit?
An eGFR below 60 (CKD Stage G3a or lower) warrants evaluation by a physician, especially if it is a new or worsening finding. An eGFR below 30 (Stage G4) typically warrants referral to a nephrologist to discuss management and preparation for renal replacement therapy. An eGFR below 15 (Stage G5) indicates kidney failure.
eGFR Calculator — CKD-EPI Kidney Function Estimator
What the eGFR Calculator Tells You About Kidney Health
The estimated Glomerular Filtration Rate (eGFR) is the most important single number for assessing kidney health. The kidneys filter approximately 200 litres of blood per day, removing waste products and excess fluid. The GFR measures the rate of this filtration. As kidney disease progresses, the GFR falls. The CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation is the most accurate formula for estimating GFR from routine blood creatinine measurements in adults. It is endorsed by the National Kidney Foundation and used in clinical laboratories worldwide. Regular eGFR monitoring is essential for anyone with diabetes, hypertension, or a family history of kidney disease.
The Five Stages of Chronic Kidney Disease
The KDIGO (Kidney Disease: Improving Global Outcomes) guidelines classify CKD into five stages based on eGFR. Stage G1 (eGFR ≥ 90) indicates normal or high function, though kidney damage may still be present (detected by protein in urine). Stage G2 (60–89) is mildly decreased. Stage G3 is split into G3a (45–59, mild-to-moderate) and G3b (30–44, moderate-to-severe). Stage G4 (15–29) is severely decreased and requires close specialist management. Stage G5 (< 15) is kidney failure, where dialysis or transplant is needed for survival. Early detection at Stages G1–G2, combined with blood pressure control and diabetes management, can slow progression significantly.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →