Glomerular filtration rate (GFR) is a test used to check how well the kidneys are working. Specifically, it estimates how much blood passes through the glomeruli each minute. Glomeruli are the tiny filters in the kidneys that filter waste from the blood.

What is normal for glomerular filtration rate?

A GFR of 60 or higher is in the normal range. A GFR below 60 may mean kidney disease. A GFR of 15 or lower may mean kidney failure.

What is calculated glomerular filtration rate?

Glomerular filtration rate is usually calculated using a mathematical formula that compares a person's size, age, sex, and race to serum creatinine levels. A GFR under 60 mL/min/1.73 m² may mean kidney disease—the lower the GFR number, the worse the kidney function. This number is an estimate.