GFR Calculator
Estimate your Glomerular Filtration Rate (GFR).
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What is Glomerular Filtration Rate (GFR)?
The Glomerular Filtration Rate (GFR) is the best overall index of kidney function. Your kidneys have tiny filters called glomeruli that help remove waste and excess fluid from the blood. The GFR is a calculation that estimates how much blood passes through these filters each minute. An estimated GFR (eGFR) is calculated from a blood creatinine test, your age, and your gender.
Stages of Chronic Kidney Disease (CKD)
The eGFR number corresponds to a stage of kidney disease. A healthcare provider will determine the stage of kidney disease based on the eGFR and other factors like the presence of protein in the urine.
- Stage 1: GFR 90 or higher (Normal or high function, with other signs of kidney damage)
- Stage 2: GFR 60-89 (Mildly decreased function, with other signs of kidney damage)
- Stage 3a: GFR 45-59 (Mildly to moderately decreased function)
- Stage 3b: GFR 30-44 (Moderately to severely decreased function)
- Stage 4: GFR 15-29 (Severely decreased function)
- Stage 5: GFR less than 15 (Kidney failure)
For more detailed information on kidney health, visit the National Kidney Foundation.
Frequently Asked Questions
What is a normal GFR?
A normal GFR is typically 90 mL/min/1.73m² or higher. However, GFR naturally declines with age, so what's normal for a 30-year-old will be different than for a 70-year-old. It's important to look at the trend of your GFR over time rather than a single number.
What does a low GFR mean?
A consistently low GFR (below 60) for three months or more is an indicator of Chronic Kidney Disease (CKD). The lower the GFR, the more significant the kidney damage. A GFR below 15 indicates kidney failure, which requires dialysis or a kidney transplant.
Can I improve my GFR?
While you cannot reverse existing kidney damage, you can take steps to slow the progression of kidney disease and preserve your remaining kidney function. This includes managing blood pressure, controlling blood sugar if you have diabetes, eating a healthy diet low in sodium, and avoiding medications that can harm the kidneys. Always consult with your doctor for personalized advice.