The Glomerular Filtration Rate (GFR) is a key indicator of kidney function. It measures how much blood passes through the glomeruli each minute. The glomeruli are tiny filters in your kidneys that remove waste products from your blood. A normal GFR is typically around 90 or higher. A GFR below 60 for three months or more may indicate chronic kidney disease (CKD).
This calculator uses the CKD-EPI 2021 creatinine equation, which is a widely accepted formula for estimating GFR. It takes into account your serum creatinine level, age, sex, and race. For more accurate results, especially if you have specific conditions, consult with your healthcare provider.
Male
Female
White
Black or African American
Asian
Other
function calculateGFR() {
var creatinine = parseFloat(document.getElementById("serumCreatinine").value);
var age = parseInt(document.getElementById("age").value);
var sex = document.getElementById("sex").value;
var race = document.getElementById("race").value;
var gfrResultElement = document.getElementById("gfrResult");
gfrResultElement.innerHTML = ""; // Clear previous result
// Input validation
if (isNaN(creatinine) || isNaN(age) || creatinine <= 0 || age <= 0) {
gfrResultElement.innerHTML = "Please enter valid positive numbers for Serum Creatinine and Age.";
return;
}
var sexFactor;
if (sex === "male") {
sexFactor = 1.018;
} else {
sexFactor = 0.954;
}
var raceFactor;
if (race === "black") {
raceFactor = 1.159;
} else {
raceFactor = 1.0; // White, Asian, Other
}
var k;
if (sex === "male") {
k = 176.7;
} else {
k = 166.0;
}
var gfr;
// CKD-EPI 2021 creatinine equation
if (creatinine = 90) {
interpretation = "Normal kidney function. However, other signs of kidney damage (like protein in urine) may still indicate CKD.";
} else if (gfr >= 60) {
interpretation = "Mildly decreased GFR. If this level persists for 3 months or more, it may indicate early stages of Chronic Kidney Disease (CKD).";
} else if (gfr >= 30) {
interpretation = "Moderately decreased GFR. This suggests a more significant stage of Chronic Kidney Disease (CKD).";
} else if (gfr >= 15) {
interpretation = "Severely decreased GFR. This indicates advanced Chronic Kidney Disease (CKD).";
} else {
interpretation = "Extremely low GFR. This suggests kidney failure, often requiring dialysis or a kidney transplant.";
}
gfrResultElement.innerHTML = "
Estimated GFR: " + gfr.toFixed(1) + " mL/min/1.73 m²