What Is a GFR Calculator?
This calculator provides an educational estimate of Glomerular Filtration Rate (eGFR), a common measure of kidney function, using the CKD-EPI 2021 equation based on age, sex, and serum creatinine — the same type of equation used by clinical labs, though actual clinical results should come from your healthcare provider and laboratory.
How to Use the GFR Calculator
- Select your sex and enter your age.
- Enter your serum creatinine level from a blood test.
- View your estimated GFR and general reference stage.
About the CKD-EPI Equation
The CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation is a widely used, clinically validated formula for estimating kidney filtration rate from creatinine, age, and sex. The 2021 version removed a previous race-based adjustment factor.
Understanding eGFR
eGFR estimates how well your kidneys filter waste from blood, expressed in mL/min/1.73m². Higher values generally indicate better kidney function. The reference stages above are commonly used general categories, but interpretation always depends on clinical context, trends over time, and other factors your healthcare provider considers.
Important: This Is Educational Only
This calculator is for general educational reference and is not a diagnosis. Kidney function assessment requires clinical evaluation by a qualified healthcare provider, who can interpret your results alongside your complete medical history, other lab values, and clinical context. Always discuss kidney function results with your doctor.
Frequently Asked Questions
Glomerular Filtration Rate measures how well your kidneys filter waste products from your blood, and is a key indicator of kidney function used by healthcare providers.
Generally, an eGFR of 90 or above is considered in the normal range, though interpretation depends on age, clinical context, and trends over time — always discuss your specific results with a healthcare provider.
It's a widely used, clinically validated formula for estimating GFR from serum creatinine, age, and sex, commonly used by clinical laboratories.
No — this tool provides an educational estimate only. Kidney disease diagnosis requires clinical evaluation by a healthcare provider, who considers your complete medical picture, not just a single calculated value.
Muscle mass, certain medications, hydration status, and other factors can affect creatinine levels and therefore estimated GFR, which is why clinical interpretation matters.