function calculateEGFR() {
var scr = parseFloat(document.getElementById('creatinine').value);
var age = parseFloat(document.getElementById('age').value);
var gender = document.getElementById('gender').value;
var display = document.getElementById('egfr-results-display');
var valueText = document.getElementById('egfr-value');
var stageText = document.getElementById('egfr-stage');
var descText = document.getElementById('egfr-desc');
if (isNaN(scr) || isNaN(age) || scr <= 0 || age = 90) {
stage = "Stage 1: Normal or High Function";
color = "#27ae60";
description = "Your GFR indicates normal kidney function. If there is evidence of kidney damage, it is classified as Stage 1 CKD.";
} else if (roundedEGFR >= 60) {
stage = "Stage 2: Mildly Decreased";
color = "#82c91e";
description = "A GFR in this range suggests mildly decreased kidney function. If kidney damage is present, it is Stage 2 CKD.";
} else if (roundedEGFR >= 45) {
stage = "Stage 3a: Mildly to Moderately Decreased";
color = "#fab005";
description = "This range indicates a moderate loss of kidney function. Consultation with a healthcare provider is recommended.";
} else if (roundedEGFR >= 30) {
stage = "Stage 3b: Moderately to Severely Decreased";
color = "#f39c12";
description = "Significant loss of kidney function. Close monitoring and management of complications are typically necessary.";
} else if (roundedEGFR >= 15) {
stage = "Stage 4: Severely Decreased";
color = "#e67e22";
description = "Severe kidney damage. It is likely you will need to discuss dialysis or kidney transplant options with a specialist.";
} else {
stage = "Stage 5: Kidney Failure";
color = "#c0392b";
description = "End-stage renal disease (ESRD). The kidneys have nearly or completely stopped working.";
}
stageText.innerText = stage;
stageText.style.backgroundColor = color;
stageText.style.color = "white";
descText.innerText = description;
}
Understanding your eGFR Result
The Estimated Glomerular Filtration Rate (eGFR) is a blood test that determines how well your kidneys are filtering waste from your blood. It is considered the most accurate way to detect kidney changes before they become problematic.
The CKD-EPI 2021 Equation
This calculator uses the CKD-EPI (2021) formula, which is the current clinical standard. Unlike older versions, this equation does not include a race-based coefficient, providing a more equitable assessment of kidney health across all populations.
Why Creatinine Matters
Creatinine is a waste product produced by muscle metabolism. When kidneys are healthy, they filter creatinine out of the blood and into the urine. If kidney function declines, creatinine levels in the blood rise. However, because creatinine levels vary based on muscle mass, the eGFR calculation adjusts the raw creatinine number based on your age and sex.
Kidney Disease Stages at a Glance
| Stage |
eGFR Range |
Meaning |
| Stage 1 |
90+ |
Normal function |
| Stage 2 |
60-89 |
Mildly decreased |
| Stage 3 |
30-59 |
Moderate decrease |
| Stage 4 |
15-29 |
Severe decrease |
| Stage 5 |
< 15 |
Kidney failure |
Realistic Example
Imagine a 60-year-old male with a serum creatinine level of 1.2 mg/dL. By entering these values into the calculator:
- Creatinine: 1.2 mg/dL
- Age: 60
- Sex: Male
- Result: eGFR ≈ 71 mL/min/1.73m² (Stage 2)
This result would suggest that while the kidneys are functioning reasonably well, there is a mild reduction in filtration capacity compared to a younger adult.
Note: This tool is for educational purposes only and should not replace professional medical advice. Always discuss your lab results with a qualified healthcare provider.