What is eGFR and Why Does It Matter?

The Estimated Glomerular Filtration Rate (eGFR) is the gold standard for assessing kidney function. It provides a numerical value that represents how well your kidneys are filtering waste products from your blood. Instead of measuring filtration directly, which is complicated, doctors use formulas like the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation based on your serum creatinine levels, age, and biological sex.

How to Use This eGFR Calculator

To use this tool, you will need a recent blood test result showing your serum creatinine levels. Enter your creatinine value in mg/dL, specify your age, and select your biological sex. Our calculator utilizes the modern 2021 CKD-EPI creatinine equation, which is the current clinical standard as it does not rely on race-based adjustments, providing a more equitable assessment of kidney health.

Understanding Your Results

A normal eGFR is typically 90 mL/min/1.73m² or higher. Results are categorized into stages of Chronic Kidney Disease (CKD):

• Stage 1 (eGFR 90+): Normal or high function, but other signs of kidney damage may be present.
• Stage 2 (eGFR 60-89): Mildly decreased function.
• Stage 3 (eGFR 30-59): Mild to moderate loss of kidney function.
• Stage 4 (eGFR 15-29): Severe loss of kidney function.
• Stage 5 (eGFR <15): Kidney failure or near-failure.

Frequently Asked Questions

Can eGFR fluctuate?

Yes. eGFR can be affected by dehydration, high-protein meals, intense exercise, or certain medications. It is important to look at trends over time rather than a single isolated reading.

Why is creatinine used?

Creatinine is a waste product from muscle breakdown. Since healthy kidneys filter it out at a consistent rate, measuring how much remains in your blood is an effective proxy for kidney efficiency.