GFR Calculator

Estimate your kidney function with the CKD-EPI formula

Calculate Your Estimated GFR

Normal range: 0.6-1.2 mg/dL

About GFR Calculation

The Glomerular Filtration Rate (GFR) is the best test to measure your level of kidney function and determine your stage of kidney disease. Our calculator uses the CKD-EPI formula, which is currently considered the most accurate estimator of GFR.

How GFR is Calculated

The CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation estimates GFR based on:

  • Serum creatinine: Waste product from muscle metabolism
  • Age: Kidney function naturally declines with age
  • Gender: Men typically have higher muscle mass than women
  • Race: Adjusts for differences in creatinine production

Understanding Your GFR Results

A GFR of 90 or above is considered normal. Values below 60 for 3 months or more indicate chronic kidney disease. Even a small decline in GFR can be significant, so regular monitoring is important for early detection of kidney problems.

Chronic Kidney Disease Stages

Stage GFR (mL/min/1.73m²) Description
1 ≥90 Normal or high kidney function
2 60-89 Mildly decreased kidney function
3a 45-59 Mild to moderate loss
3b 30-44 Moderate to severe loss
4 15-29 Severely decreased kidney function
5 <15 Kidney failure (end-stage renal disease)

Limitations of eGFR

While eGFR is a valuable screening tool, it has some limitations:

  • Less accurate for people with extreme muscle mass (athletes, bodybuilders)
  • May be less reliable for the elderly or malnourished individuals
  • Doesn't account for rapid changes in kidney function
  • Should be interpreted in clinical context with other tests