GFR Calculator
Use our GFR calculator
To calculate your eGFR, enter all fields below.
This eGFR value may indicate:
What is GFR?
Your exact GFR cannot be measured directly. Instead, our GFR calculator will give you an estimate using a mathematical formula that most closely determines your kidney function based on certain personal factors and your serum creatinine, which is the amount of creatinine in your blood.
What is estimated GFR?
Your estimated glomerular filtration rate (eGFR) is the calculation that indicates your level of kidney function, based on the results of a creatinine serum test and other factors—such as age and gender. If your eGFR is below 90, your kidneys may not be functioning as well as they should and you may be at risk for kidney disease.
By estimating your GFR, along with other blood and urine tests, your doctor is able to diagnose kidney disease, determine which stage you’re in, and track any progression. Knowing your eGFR is also important to managing your health at every stage of kidney disease.
How to calculate your GFR
Estimating GFR begins with a simple serum creatinine blood test. If you’re using our GFR calculator, your eGFR is calculated using the results of your blood test, along with your age and gender. When your eGFR is calculated by your doctor, weight and body size may also be factored into your eGFR.
What does your GFR mean for you?
Your eGFR helps identify your level of kidney function. Each stage of kidney disease matches up to an eGFR range, and knowing which stage you’re in can help you identify the steps you need to take to stay your healthiest. People in early stages 1-3, for example, may want to focus on managing kidney health and slowing kidney disease progression by eating well, taking medications as prescribed, managing any comorbid conditions, and starting to see a nephrologist (kidney doctor). People in stages 4-5 of CKD should start learning about their treatment options, like kidney transplant and dialysis.
Use the chart below to determine which CKD stage best matches your GFR calculator results and click on the stage to learn about healthy next steps.
STAGE 1 | Kidney damage with normal kidney function | eGFR of 90 or higher |
STAGE 2 | Mild loss of kidney function | eGFR of 60–89 |
STAGE 3A | Mild to moderate loss of kidney function | eGFR of 45–59 |
STAGE 3B | Moderate to severe loss of kidney function | eGFR of 30–44 |
STAGE 4 | Severe loss of kidney function | eGFR of 15–29 |
STAGE 5 - END STAGE RENAL DISEASE (ESRD) |
Kidney failure or close to kidney failure | eGFR of less than 15 |
What are normal GFR levels?
What can affect GFR levels?
If you are diagnosed with chronic kidney disease, it’s also important to understand the root cause of the condition to protect your remaining kidney function and keep your GFR levels in a healthy range. Managing other conditions like high blood pressure or diabetes can help you stay healthy and slow the progression of CKD. In some cases, your care team may recommend changing your medications or daily routine to prevent further kidney damage.
Why knowing your GFR matters
Your eGFR is an important calculation that helps your doctor determine your level of kidney function. This can mean something different for everybody, since your eGFR also depends on your age, gender, muscle mass, and creatinine serum test results. If your doctor is using eGFR to help diagnose kidney disease or determine your stage, you may also need additional tests to confirm.
Knowing your eGFR and understanding which stage you’re in can help you take steps to preserve kidney function and track any progression.