eGFR Calculator

What Is eGFR?

Estimated glomerular filtration rate (eGFR) measures how well your kidneys filter waste from your blood. It is calculated from your blood creatinine level, age, sex, and sometimes race, using the CKD-EPI equation – the current clinical standard. A normal eGFR is 90 or above. Lower values indicate reduced kidney function, which may require monitoring, treatment, or lifestyle adjustments to slow further decline.

eGFR Stages and What They Mean

Stage 1 (eGFR 90+): normal kidney function. Stage 2 (60–89): mildly reduced, often no symptoms. Stage 3a (45–59): mild to moderate reduction. Stage 3b (30–44): moderate to severe. Stage 4 (15–29): severe reduction, referral to a nephrologist is recommended. Stage 5 (below 15): kidney failure, dialysis or transplant may be needed. Many people with Stage 2 or early Stage 3 have no symptoms and discover reduced function through routine blood work.

How eGFR Is Calculated

The CKD-EPI 2021 equation uses serum creatinine, age, and sex. Creatinine is a waste product from normal muscle metabolism that your kidneys filter out. When kidney function declines, creatinine accumulates in the blood. This calculator applies the CKD-EPI formula to your lab values and classifies your result by CKD stage. Note that muscle mass, diet (especially high-protein intake), and hydration can temporarily affect creatinine levels and therefore the eGFR estimate.

Protecting Kidney Health

Managing blood pressure and blood sugar are the two most important steps for preserving kidney function. High blood pressure and diabetes are responsible for roughly two-thirds of all chronic kidney disease cases. Staying hydrated, limiting sodium intake to under 2,300 mg per day, maintaining a healthy weight, and avoiding excessive use of NSAIDs (ibuprofen, naproxen) all support kidney health. If your eGFR is below 60, your doctor may recommend dietary protein adjustments and closer monitoring of kidney function over time.

Frequently asked questions