Glomerular Filtration Rate (GFR) Calculator
Estimate your GFR using the CKD-EPI 2021 race-free equation.
Enter your details and click "Calculate GFR".
Understanding Glomerular Filtration Rate (GFR)
The Glomerular Filtration Rate (GFR) is a crucial measure of kidney function. It estimates how much blood passes through the glomeruli each minute. Glomeruli are tiny filters in your kidneys that remove waste products and excess water from your blood. A healthy GFR indicates that your kidneys are effectively cleaning your blood.
Why is GFR Important?
Monitoring GFR is vital for detecting and managing kidney disease. A declining GFR can be an early sign of kidney damage, allowing for timely intervention to slow its progression. It helps healthcare providers:
- Diagnose chronic kidney disease (CKD).
- Stage the severity of CKD.
- Monitor the effectiveness of treatments.
- Adjust medication dosages that are cleared by the kidneys.
How is GFR Calculated?
Directly measuring GFR is complex and usually involves injecting a tracer substance. Therefore, GFR is typically estimated using formulas that incorporate readily available blood test results, primarily serum creatinine, along with age, sex, and sometimes other factors. Our calculator uses the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) 2021 equation, which is a widely accepted and race-free formula for estimating GFR.
The CKD-EPI 2021 equation is considered more accurate than older formulas like MDRD, especially for individuals with GFR values close to normal. It helps provide a more precise assessment of kidney health across diverse populations.
Interpreting Your GFR Results
GFR values are typically reported in milliliters per minute per 1.73 square meters (mL/min/1.73m²), which adjusts the result for average body surface area. Here's a general guide to interpreting GFR values:
- 90 or higher: Normal kidney function.
- 60-89: Mildly decreased kidney function. Often indicates early kidney disease, especially if there are other signs of kidney damage (e.g., protein in urine).
- 45-59: Moderately decreased kidney function (Stage 3a CKD).
- 30-44: Moderately to severely decreased kidney function (Stage 3b CKD).
- 15-29: Severely decreased kidney function (Stage 4 CKD).
- Less than 15: Kidney failure (Stage 5 CKD), often requiring dialysis or kidney transplant.
It's important to remember that a single GFR reading doesn't tell the whole story. Trends over time, along with other clinical information, provide a more complete picture of kidney health. Always discuss your GFR results with a healthcare professional for an accurate diagnosis and personalized advice.
Disclaimer: This GFR calculator is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Consult with a qualified healthcare provider for any health concerns or before making any decisions related to your health or treatment.