What is Glomerular Filtration Rate (GFR)?

Glomerular Filtration Rate (GFR) is a measure of how well your kidneys are filtering waste from your blood. It is considered the best overall indicator of kidney function. This calculator provides an estimated GFR (eGFR).

Why does this calculator ask for race?

The standard CKD-EPI formula includes race as a variable because population studies showed differences in creatinine levels. However, the use of race in medical algorithms is under review in the medical community, and newer race-free equations are being developed. This calculator uses the standard 2009 formula.

Can I use this calculator for medical decisions?

Absolutely not. This calculator is for informational purposes only. GFR values and kidney health should be interpreted by a qualified doctor who can consider your complete medical history. Do not make any medical decisions based on this tool.

GFR Calculator (CKD-EPI Formula)

CRITICAL MEDICAL DISCLAIMER: This calculator is for informational purposes only and is NOT a substitute for professional medical advice, diagnosis, or treatment. GFR results must be interpreted by a qualified physician. DO NOT make any medical decisions based on this tool.

Your Estimated GFR (eGFR) Result

Your eGFR is:

mL/min/1.73m²

Stages of Kidney Disease (Based on GFR)

Stage	GFR Level (mL/min/1.73m²)	Description
1	≥ 90	Normal or high kidney function
2	60-89	Mildly decreased kidney function
3a	45-59	Mild to moderately decreased kidney function
3b	30-44	Moderately to severely decreased kidney function
4	15-29	Severely decreased kidney function
5	< 15	Kidney failure

Understanding Your GFR Result

The Glomerular Filtration Rate (GFR) is the best measure of kidney function. It estimates how much blood passes through the tiny filters (glomeruli) in your kidneys each minute. A low GFR indicates that your kidneys are not working as well as they should.

This calculator provides an **estimated GFR (eGFR)** using the CKD-EPI formula, which requires a serum creatinine value from a blood test. The result helps doctors determine the stage of kidney disease and plan appropriate management. Again, this tool is purely for educational purposes—all results must be discussed with a healthcare provider.

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Frequently Asked Questions (FAQ)

What is Serum Creatinine?

Creatinine is a waste product that comes from the normal wear and tear on muscles of the body. Healthy kidneys filter creatinine out of the blood. When kidney function is impaired, creatinine levels in the blood rise. This value is obtained from a simple blood test.

Why does the formula include age, gender, and race?

These factors are included in the CKD-EPI equation because they are known to influence creatinine levels in the blood, independent of kidney function. For example, men generally have more muscle mass than women, leading to higher creatinine levels. The race factor was included based on population studies, though its use is currently being debated and may be removed in future formulas.

What should I do if my eGFR is low?

If you have received a low eGFR result from a lab test, it is crucial to speak with your doctor. They will interpret the result in the context of your overall health, may order further tests, and will recommend the best course of action to protect your kidney health. Do not rely on online tools for any health decisions.