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.

Your GFR tells your doctor your stage of kidney disease and helps the doctor plan your treatment. If your GFR number is low, your kidneys are not working as well as they should. The earlier kidney disease is detected, the better the chance of slowing or stopping its progression.

GFR Number by Age The normal range of Kidney Glomerular Filtration Rate is 100 to 130 mL/min/1.73m2 in men and 90 to 120mL/min/1.73m2 in women below the age of 40. GFR decreases progressively after the age of 40 years.