The Estimated Glomerular Filtration Rate (eGFR) is a key metric used by healthcare providers to assess how well your kidneys are functioning. It estimates the volume of blood filtered by the kidneys per minute based on the level of creatinine in your blood, your age, and your biological sex.
This calculator uses the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) 2021 formula, which is the current clinical standard. Unlike previous versions, the 2021 formula does not include a race variable, making it more accurate and equitable across diverse populations.
Understanding Your Results
An eGFR result is measured in mL/min/1.73m². Doctors typically categorize kidney function into several stages:
eGFR Range
Stage
Description
90 or above
Stage 1
Normal kidney function
60 – 89
Stage 2
Mildly decreased function
45 – 59
Stage 3a
Mildly to moderately decreased
30 – 44
Stage 3b
Moderately to severely decreased
15 – 29
Stage 4
Severely decreased function
Below 15
Stage 5
Kidney failure (End-stage)
Example Calculation
If a 55-year-old male has a serum creatinine of 1.2 mg/dL, his eGFR calculation would be approximately 74 mL/min/1.73m², placing him in Stage 2 (Mildly decreased function).
Why eGFR Matters
Early detection of Chronic Kidney Disease (CKD) is vital because kidney damage is often asymptomatic in its early stages. By monitoring eGFR, medical professionals can implement lifestyle changes or medication adjustments to slow the progression of kidney damage.
Note: This calculator is for educational purposes only. Always consult with a qualified medical professional to interpret lab results and diagnose health conditions.
function calculateEGFR() {
var creatinine = parseFloat(document.getElementById('creatinine_val').value);
var age = parseFloat(document.getElementById('age_val').value);
var sex = document.getElementById('sex_val').value;
var resultArea = document.getElementById('egfr-result-area');
var scoreDisplay = document.getElementById('final_score');
var interpretationText = document.getElementById('interpretation_text');
if (isNaN(creatinine) || isNaN(age) || creatinine <= 0 || age = 90) {
statusClass = "status-normal";
stageText = "Stage 1: Normal kidney function. Keep maintaining a healthy lifestyle.";
} else if (finalScore >= 60) {
statusClass = "status-mild";
stageText = "Stage 2: Mildly decreased kidney function. This may be normal depending on your age and health history.";
} else if (finalScore >= 45) {
statusClass = "status-moderate";
stageText = "Stage 3a: Mildly to moderately decreased kidney function. Consult your physician for a check-up.";
} else if (finalScore >= 30) {
statusClass = "status-moderate";
stageText = "Stage 3b: Moderately to severely decreased kidney function. Close monitoring by a specialist (nephrologist) is often recommended.";
} else if (finalScore >= 15) {
statusClass = "status-severe";
stageText = "Stage 4: Severely decreased kidney function. This indicates significant kidney damage.";
} else {
statusClass = "status-severe";
stageText = "Stage 5: Kidney failure or near-failure. Immediate medical evaluation is necessary.";
}
resultArea.className = "";
resultArea.classList.add(statusClass);
interpretationText.innerHTML = stageText;
}