Convert your finger-stick glucose readings to A1C or vice versa using the ADAG formula.
mg/dL (USA Standard)
mmol/L (International Standard)
Estimated HbA1c
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Estimated Average Glucose (eAG)
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How to Calculate A1C: Understanding the Formula
The A1C test (glycated hemoglobin) measures your average blood sugar levels over the past two to three months. Unlike a daily finger-stick test which shows your sugar at a single moment, A1C provides a "big picture" view of your diabetes management.
The A1C Calculation Formula
The relationship between the A1C percentage and Estimated Average Glucose (eAG) is determined by the ADAG (A1C-Derived Average Glucose) study. The standard mathematical formulas are:
To get A1C from mg/dL:A1C = (Average Glucose + 46.7) / 28.7
To get eAG (mg/dL) from A1C:eAG = (28.7 * A1C) - 46.7
A1C Conversion Examples
If your average daily glucose readings hover around 154 mg/dL, your A1C would be calculated as follows:
(154 + 46.7) / 28.7 = 6.99% (Approximately 7.0%)
Interpreting Your Results
Healthcare providers typically use the following ranges for A1C levels:
A1C Level
Category
Below 5.7%
Normal
5.7% to 6.4%
Prediabetes
6.5% or Above
Diabetes
Disclaimer: This calculator is for educational purposes only. Always consult with a medical professional for diagnosis and treatment of diabetes.
function switchTab(target) {
var sectionA1C = document.getElementById('section-to-a1c');
var sectionEAG = document.getElementById('section-to-eag');
var btnA1C = document.getElementById('btn-to-a1c');
var btnEAG = document.getElementById('btn-to-eag');
if (target === 'to-a1c') {
sectionA1C.classList.remove('hidden');
sectionEAG.classList.add('hidden');
btnA1C.classList.add('active');
btnEAG.classList.remove('active');
} else {
sectionA1C.classList.add('hidden');
sectionEAG.classList.remove('hidden');
btnA1C.classList.remove('active');
btnEAG.classList.add('active');
}
}
function calculateA1C() {
var glucoseInput = document.getElementById('glucose_val').value;
var unit = document.getElementById('unit_type').value;
var resultDiv = document.getElementById('a1c-result-box');
var output = document.getElementById('a1c-output');
var status = document.getElementById('a1c-status');
if (!glucoseInput || glucoseInput <= 0) {
alert("Please enter a valid glucose value.");
return;
}
var mgdl = parseFloat(glucoseInput);
if (unit === 'mmol') {
mgdl = mgdl * 18.0182;
}
// Formula: A1C = (eAG + 46.7) / 28.7
var a1c = (mgdl + 46.7) / 28.7;
var finalA1C = a1c.toFixed(1);
output.innerHTML = finalA1C + "%";
resultDiv.style.display = 'block';
// Interpret Status
if (a1c = 5.7 && a1c < 6.5) {
status.innerHTML = "Prediabetes Range";
status.className = "status-badge status-pre";
} else {
status.innerHTML = "Diabetes Range";
status.className = "status-badge status-diabetes";
}
}
function calculateEAG() {
var a1cInput = document.getElementById('a1c_input').value;
var resultDiv = document.getElementById('eag-result-box');
var outputMg = document.getElementById('eag-output-mg');
var outputMmol = document.getElementById('eag-output-mmol');
if (!a1cInput || a1cInput <= 0) {
alert("Please enter a valid A1C percentage.");
return;
}
var a1cVal = parseFloat(a1cInput);
// Formula: eAG = (28.7 * A1C) – 46.7
var eagMgdl = (28.7 * a1cVal) – 46.7;
var eagMmol = eagMgdl / 18.0182;
outputMg.innerHTML = Math.round(eagMgdl) + " mg/dL";
outputMmol.innerHTML = "Equivalent to " + eagMmol.toFixed(1) + " mmol/L";
resultDiv.style.display = 'block';
}