How to Calculate A1c from Glucose

A1C from Average Glucose Calculator

Enter your estimated Average Glucose (eAG) to calculate your estimated A1C percentage.

function calculateA1C() { var averageGlucoseInput = document.getElementById("averageGlucose").value; var unitMgdl = document.getElementById("unitMgdl").checked; var unitMmol = document.getElementById("unitMmol").checked; var resultDiv = document.getElementById("a1cResult"); var averageGlucose = parseFloat(averageGlucoseInput); if (isNaN(averageGlucose) || averageGlucose <= 0) { resultDiv.innerHTML = "Please enter a valid positive number for Average Blood Glucose."; return; } var estimatedA1C; if (unitMgdl) { // Formula for mg/dL: eA1C (%) = (eAG (mg/dL) + 46.7) / 28.7 estimatedA1C = (averageGlucose + 46.7) / 28.7; } else if (unitMmol) { // Formula for mmol/L: eA1C (%) = (eAG (mmol/L) + 2.59) / 1.59 estimatedA1C = (averageGlucose + 2.59) / 1.59; } else { resultDiv.innerHTML = "Please select a unit for Average Blood Glucose."; return; } resultDiv.innerHTML = "Estimated A1C: " + estimatedA1C.toFixed(2) + "%"; }

Understanding A1C and Average Glucose (eAG)

The A1C test, also known as the hemoglobin A1C or HbA1c test, is a common blood test used to diagnose type 2 diabetes and prediabetes, and to monitor diabetes management. It measures your average blood sugar (glucose) levels over the past two to three months.

What is A1C?

A1C measures the percentage of your red blood cells that have glucose attached to them (glycated hemoglobin). Since red blood cells live for about 2-3 months, the A1C test provides a good long-term picture of your blood sugar control. A higher A1C percentage indicates higher average blood sugar levels, which can increase the risk of diabetes-related complications.

• Normal A1C: Below 5.7%
• Prediabetes: 5.7% to 6.4%
• Diabetes: 6.5% or higher

What is Estimated Average Glucose (eAG)?

Estimated Average Glucose (eAG) is a term used to describe your average blood glucose level over time, expressed in the same units (mg/dL or mmol/L) that you typically see on your home blood glucose meter. It's a way to translate your A1C percentage into a more familiar average blood sugar number, making it easier to understand what your A1C result means in terms of daily glucose levels.

How is A1C Calculated from eAG?

While A1C is usually measured directly in a lab, an estimated A1C can be derived from your average blood glucose (eAG) using specific formulas. These formulas are based on extensive research and provide a good approximation:

• If eAG is in mg/dL: Estimated A1C (%) = (eAG (mg/dL) + 46.7) / 28.7
• If eAG is in mmol/L: Estimated A1C (%) = (eAG (mmol/L) + 2.59) / 1.59

This calculator uses these standard formulas to convert your average glucose reading into an estimated A1C percentage.

Why Convert Between A1C and eAG?

Converting between A1C and eAG can be helpful for several reasons:

• Better Understanding: If you regularly monitor your blood sugar with a meter, seeing your A1C translated into an average daily glucose level can help you better understand your long-term control.
• Communication with Healthcare Providers: It facilitates discussions with your doctor, as both values provide different perspectives on your glucose management.
• Goal Setting: It can help in setting more tangible daily blood sugar goals to achieve a desired A1C target.

Important Disclaimer:

This calculator provides an estimated A1C based on your average glucose input. It is not a substitute for a laboratory A1C test performed by a healthcare professional. Always consult with your doctor or a qualified healthcare provider for accurate diagnosis, treatment, and management of diabetes or any health concerns.