GFR Calculator - Estimate Kidney Function (CKD-EPI 2021)

What is GFR?

Glomerular Filtration Rate (GFR) is the best overall index of kidney function. It estimates how much blood passes through the glomeruli (tiny filters in the kidneys) each minute.

Since directly measuring GFR is difficult, medical professionals use eGFR (estimated GFR) based on the level of creatinine in the blood. Creatinine is a waste product from muscle wear and tear that healthy kidneys filter out.

Calculation Method (CKD-EPI 2021)

This calculator uses the 2021 CKD-EPI Creatinine Equation recommended by the National Kidney Foundation.

Accuracy: It is more accurate than the older MDRD or Cockcroft-Gault formulas, especially for higher GFR values.
Race-Neutral: Unlike previous versions, the 2021 equation does not use a race coefficient, ensuring more equitable diagnosis for all patients.

Interpreting Your Score

90 or higher: Normal kidney function (if no other signs of kidney damage are present).
60-89: Mildly reduced function. Often typical with aging.
Below 60: May indicate Chronic Kidney Disease (CKD) if persistent for over 3 months.
Below 15: Indicates kidney failure, requiring dialysis or transplant.

Disclaimer: This tool is for informational purposes only. Do not use it to diagnose medical conditions. Always consult a nephrologist or healthcare provider for interpretation of lab results.

? Frequently Asked Questions

GFR naturally declines with age. A 20-year-old might have a GFR of 116, while a healthy 70-year-old might have a GFR of 75. This is normal aging.

The updated 2021 CKD-EPI equation removed the race coefficient to eliminate racial bias in medical algorithms. This is the new standard endorsed by the National Kidney Foundation.

While you cannot reverse scarring, you can protect remaining function by managing blood pressure, controlling blood sugar, staying hydrated, and avoiding nephrotoxic medications (like NSAIDs).