GFR Calculator

- April 25, 2025
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Calculate estimated Glomerular Filtration Rate (eGFR) using the MDRD or CKD-EPI equations. GFR measures how well your kidneys filter blood and helps detect kidney disease.

Patient Information

Laboratory Values

Advanced Options

About GFR and Kidney Function

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

GFR Classification and CKD Stages
GFR (mL/min/1.73m²) CKD Stage Kidney Function
≥90 Stage 1 (with other evidence of kidney damage) Normal or High
60-89 Stage 2 (with other evidence of kidney damage) Mildly Decreased
45-59 Stage 3a Mildly to Moderately Decreased
30-44 Stage 3b Moderately to Severely Decreased
15-29 Stage 4 Severely Decreased
<15 Stage 5 Kidney Failure
Calculation Methods
  • CKD-EPI Equation (2009): The most accurate method for estimating GFR, especially for higher GFR values (>60 mL/min/1.73m²). Recommended for general clinical use.
  • MDRD Equation (4-variable): An older formula that may underestimate GFR in healthier individuals with values >60 mL/min/1.73m².
Important Notes
  • This calculator provides an estimate of GFR based on serum creatinine. For more accurate kidney function assessment, consult with a healthcare provider.
  • GFR calculations are less reliable at extremes of age and body size.
  • A single GFR measurement should not be used to diagnose kidney disease. Persistent abnormalities for >3 months are needed for chronic kidney disease diagnosis.
  • Additional tests (e.g., urine albumin-to-creatinine ratio) may be needed to fully assess kidney health.

Understanding the GFR Calculator

The GFR Calculator is designed to help you estimate your Glomerular Filtration Rate, or eGFR. This rate gives important information about how well your kidneys are functioning. By using either the MDRD or CKD-EPI equations, this tool can help identify potential kidney issues early on. Knowing your GFR can assist in managing your Health better.

Why GFR Matters

GFR is a key indicator of kidney health. A healthy GFR means your kidneys are filtering blood effectively. If the GFR is low, it may suggest a decline in kidney function. Regular monitoring can aid in preventing more serious kidney problems down the line. Here are some key reasons why GFR is important:

  • Helps detect kidney disease early.
  • Guides treatment options and lifestyle changes.
  • Monitors progression of existing kidney issues.

Inputting Patient Information

To get the most accurate results, you'll need to provide specific patient details. This includes age, gender, and race. These factors can affect the GFR calculation. Accurate input helps ensure that the tool estimates your kidney function correctly. Make sure to fill in all required fields for the best outcomes.

Laboratory Values Explained

Another key part of the GFR Calculator is inputting your serum creatinine level. This measurement tells us how well your kidneys are filtering waste from your blood. The calculator can take values in both mg/dL and μmol/L. Being aware of your creatinine levels is crucial for understanding your overall kidney health.

Advanced Options for Precision

For users who want more control, the GFR Calculator offers advanced options. You can choose the number of decimal places for your results. Plus, there's an option to view the calculation details. This feature can be especially helpful if you're curious about how the estimate is determined. More precision can lead to better insights about your health.

The Results You Can Expect

Once you enter all the necessary information, the calculator provides a range of results. You’ll see your estimated GFR, CKD stage, and kidney function status. Each of these categories gives critical insights into your kidney health. Understanding these results can help you have informed conversations with your healthcare provider.

Interpreting Your GFR Results

Understanding the meaning behind your GFR results is crucial. The estimated GFR value will tell you about your kidney function, while the CKD stage will indicate where you stand in terms of kidney health. Here’s a quick look at what different GFR values mean:

  • ≥90: Normal or high function
  • 60-89: Mildly decreased function
  • 15-29: Severely decreased function
  • <15: Kidney failure

Consulting a Healthcare Provider

While the GFR Calculator provides useful estimates, it's important to consult with a healthcare provider for a complete assessment. They can offer more accurate tests and guidance tailored to your specific situation. Relying solely on the calculator isn't advisable, especially if you have ongoing health concerns.