Glomerular Filtration Rate (GFR)

What is GFR? - GFR Calculator

GFR - glomerular filtration rate is the best test to measure your level of kidney function and determine your stage of kidney disease. Your doctor can calculate it from the results of your blood creatinine test, your age, body size and gender. The earlier kidney disease is detected, the better the chance of slowing or stopping its progression.

Your GFR tells your doctor your stage of kidney disease and helps the doctor plan your treatment. Your doctor can calculate it from your blood creatinine, your age, body size and gender.

Stages of CKD

Stage Description Glomerular Filtration Rate GFR)
At increased risk Risk factors for kidney disease (e.g., diabetes, high blood pressure, family history, older age, ethnic group) More than 90
1 Kidney damage (protein in the urine) and normal GFR More than 90
2 Kidney damage and mild decrease in GFR 60 to 89
3 Moderate decrease in GFR 30 to 59
4 Severe decrease in GFR 15 to 29
5 Kidney failure (dialysis or kidney transplant needed) Less than 15

What happens if my test results show I may have chronic kidney disease?

Your doctor will want to pinpoint your diagnosis and check your kidney function to help plan your treatment. The doctor may do the following:

  • Calculate your Glomerular Filtration Rate (GFR), which is the best way to tell how much kidney function you have. You do not need to have another test to know your GFR. Your doctor can calculate it from your blood creatinine, your age, body size and gender. Your GFR tells your doctor your stage of kidney disease and helps the doctor plan your treatment. (See arrow "Stages of Chronic Kidney Disease.")
  • Perform an ultrasound or CT scan to get a picture of your kidneys and urinary tract. This tells your doctor whether your kidneys are too large or too small, whether you have a problem like a kidney stone or tumor and whether there are any problems in the structure of your kidneys and urinary tract.
  • Perform a kidney biopsy, which is done in some cases to check for a specific type of kidney disease, see how much kidney damage has occurred and help plan treatment. To do a biopsy, the doctor removes small pieces of kidney tissue and looks at them under a microscope.

Your doctor may also ask you to see a specialist who will consult on your case and help manage your care.

If you would like more information, please contact us.

©2013 National Kidney Foundation. All rights reserved. This material does not constitute medical advice. It is intended for informational purposes only. No one associated with the National Kidney Foundation will answer medical questions via e-mail. Please consult a physician for specific treatment recommendations.