In adults, normal glomerular filtration rate levels range from 90 to 120 mL/min/1.73 m2, according to MedlinePlus. Levels below 60 mL/min/1.73 m2 that persist for at least three months signify chronic kidney disease, and a GFR level below 15 mL/min/1.73 m2 indicates kidney failure.
GFR tests help practitioners determine how well the kidneys filter waste from the blood, explains MedlinePlus. Normal GFR levels may vary slightly depending on the specific lab test used or the age of the patient. Older patients typically have lower GFR levels since normal value ranges decrease with age. Healthy children also have lower normal GFR levels. Normal GFR levels for children and the elderly range from 60 to 89 mL/min/1.73 m2, according to Healthline.