About eGFR Calculator

What is eGFR?

eGFR stands for estimated Glomerular Filtration Rate, which is the best test to measure your level of kidney function and determine your stage of kidney disease. Your eGFR tells your doctor how much kidney function you have.

Why is eGFR Important?

The eGFR is an essential tool for:

• Detecting kidney disease
• Monitoring progression of kidney disease
• Guiding treatment decisions
• Adjusting medication dosages that are cleared by the kidneys
• Determining the stage of chronic kidney disease (CKD)

eGFR Equations Explained

Several equations are used to calculate eGFR, each with its own advantages and limitations:

CKD-EPI Equation (2021)

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is currently the most accurate formula for estimating GFR. The 2021 revision removed the race coefficient, making it more equitable across different populations. It uses serum creatinine, age, and sex to estimate GFR.

MDRD Study Equation

The Modification of Diet in Renal Disease (MDRD) Study equation was widely used before CKD-EPI. It tends to underestimate GFR in the higher ranges, making it less accurate for people with mild kidney impairment.

Cockcroft-Gault Formula

The Cockcroft-Gault formula estimates creatinine clearance rather than GFR directly. It's often used for medication dosing and incorporates weight in its calculation.

CKD-EPI Cystatin C Equation

This equation uses cystatin C instead of creatinine. Cystatin C is less affected by muscle mass and dietary protein, potentially making it more accurate for certain populations.

CKD-EPI Creatinine-Cystatin C Equation

This combined equation uses both creatinine and cystatin C measurements, which can provide improved accuracy compared to equations using either marker alone.

Schwartz Bedside Formula

This formula is specifically designed for children and adolescents, as regular adult equations are not accurate for pediatric populations.

Understanding Your eGFR Results

eGFR results are typically reported in mL/min/1.73m². Here's what different ranges generally indicate:

• 90 or higher: Normal kidney function
• 60-89: Mildly decreased kidney function
• 45-59: Mild to moderate decrease in kidney function (CKD Stage 3a)
• 30-44: Moderate to severe decrease in kidney function (CKD Stage 3b)
• 15-29: Severe decrease in kidney function (CKD Stage 4)
• Less than 15: Kidney failure (CKD Stage 5)

Factors That Can Affect eGFR

Several factors can influence eGFR results:

• Age (kidney function naturally decreases with age)
• Muscle mass (can affect creatinine levels)
• Diet (high protein meals can affect creatinine)
• Medications
• Hydration status
• Pregnancy
• Acute illness

About This Calculator

Our eGFR calculator provides healthcare professionals and patients with a user-friendly tool to calculate estimated GFR using multiple established formulas. The calculator is designed to be accurate, accessible, and educational, helping users understand kidney function assessment better.