A1c Glucose Calculator

A1C to Estimated Average Glucose (eAG) Converter

Enter one value to convert:

function calculateFromA1C() { var a1c = parseFloat(document.getElementById("a1cInput").value); if (isNaN(a1c) || a1c <= 0) { alert("Please enter a valid positive A1C percentage."); clearResults(); return; } // Clear other inputs document.getElementById("eagMgdlInput").value = ""; document.getElementById("eagMmolInput").value = ""; // A1C to eAG (mg/dL) formula: eAG (mg/dL) = (28.7 * A1C) – 46.7 var eagMgdl = (28.7 * a1c) – 46.7; // A1C to eAG (mmol/L) formula: eAG (mmol/L) = (1.59 * A1C) – 2.59 var eagMmol = (1.59 * a1c) – 2.59; document.getElementById("resultA1C").innerText = a1c.toFixed(1) + "%"; document.getElementById("resultEAGMgdl").innerText = eagMgdl.toFixed(0); document.getElementById("resultEAGMmol").innerText = eagMmol.toFixed(1); } function calculateFromMgdl() { var eagMgdl = parseFloat(document.getElementById("eagMgdlInput").value); if (isNaN(eagMgdl) || eagMgdl <= 0) { alert("Please enter a valid positive eAG (mg/dL) value."); clearResults(); return; } // Clear other inputs document.getElementById("a1cInput").value = ""; document.getElementById("eagMmolInput").value = ""; // eAG (mg/dL) to A1C formula: A1C = (eAG (mg/dL) + 46.7) / 28.7 var a1c = (eagMgdl + 46.7) / 28.7; // eAG (mg/dL) to eAG (mmol/L) conversion: 1 mg/dL = 0.0555 mmol/L var eagMmol = eagMgdl * 0.0555; document.getElementById("resultA1C").innerText = a1c.toFixed(1) + "%"; document.getElementById("resultEAGMgdl").innerText = eagMgdl.toFixed(0); document.getElementById("resultEAGMmol").innerText = eagMmol.toFixed(1); } function calculateFromMmol() { var eagMmol = parseFloat(document.getElementById("eagMmolInput").value); if (isNaN(eagMmol) || eagMmol <= 0) { alert("Please enter a valid positive eAG (mmol/L) value."); clearResults(); return; } // Clear other inputs document.getElementById("a1cInput").value = ""; document.getElementById("eagMgdlInput").value = ""; // eAG (mmol/L) to A1C formula: A1C = (eAG (mmol/L) + 2.59) / 1.59 var a1c = (eagMmol + 2.59) / 1.59; // eAG (mmol/L) to eAG (mg/dL) conversion: 1 mmol/L = 18.0182 mg/dL var eagMgdl = eagMmol * 18.0182; document.getElementById("resultA1C").innerText = a1c.toFixed(1) + "%"; document.getElementById("resultEAGMgdl").innerText = eagMgdl.toFixed(0); document.getElementById("resultEAGMmol").innerText = eagMmol.toFixed(1); } function clearAll() { document.getElementById("a1cInput").value = ""; document.getElementById("eagMgdlInput").value = ""; document.getElementById("eagMmolInput").value = ""; clearResults(); } function clearResults() { document.getElementById("resultA1C").innerText = "-"; document.getElementById("resultEAGMgdl").innerText = "-"; document.getElementById("resultEAGMmol").innerText = "-"; }

Understanding A1C and Estimated Average Glucose (eAG)

The A1C test, also known as the hemoglobin A1C or HbA1c test, is a crucial blood test used to diagnose type 2 diabetes and prediabetes, and to monitor blood sugar control in people with diabetes. It provides an average of your blood glucose levels over the past two to three months.

What is A1C?

Hemoglobin is a protein in your red blood cells that carries oxygen. Glucose in your blood attaches to hemoglobin. The A1C test measures the percentage of hemoglobin that is coated with sugar (glycated). A higher A1C percentage indicates higher average blood sugar levels.

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

What is Estimated Average Glucose (eAG)?

While A1C is a percentage, many people are more familiar with blood glucose readings in mg/dL (milligrams per deciliter) or mmol/L (millimoles per liter), which are used for daily blood sugar monitoring. Estimated Average Glucose (eAG) is a term that converts your A1C result into the same units (mg/dL or mmol/L) that you see on your home blood glucose meter. This makes it easier to understand your long-term blood sugar control in a more familiar context.

The conversion formulas used in this calculator are based on the A1C-Derived Average Glucose (ADAG) study, which established a strong correlation between A1C and average glucose levels.

• eAG (mg/dL) = (28.7 × A1C) – 46.7
• eAG (mmol/L) = (1.59 × A1C) – 2.59

Why is this Conversion Important?

Converting A1C to eAG helps individuals with diabetes and their healthcare providers to:

• Bridge the gap: Understand how their A1C (long-term average) relates to their daily blood sugar readings.
• Set goals: Translate A1C goals into daily average glucose targets.
• Improve communication: Facilitate discussions about blood sugar control using familiar units.

Examples of A1C and eAG Conversions:

Let's look at some realistic examples:

• If your A1C is 6.5%:
  • eAG (mg/dL) = (28.7 × 6.5) – 46.7 = 186.55 – 46.7 = 139.85 mg/dL (approximately 140 mg/dL)
  • eAG (mmol/L) = (1.59 × 6.5) – 2.59 = 10.335 – 2.59 = 7.745 mmol/L (approximately 7.7 mmol/L)
• If your eAG is 126 mg/dL:
  • A1C = (126 + 46.7) / 28.7 = 172.7 / 28.7 = 6.017% (approximately 6.0%)
  • eAG (mmol/L) = 126 × 0.0555 = 6.993 mmol/L (approximately 7.0 mmol/L)
• If your eAG is 7.0 mmol/L:
  • A1C = (7.0 + 2.59) / 1.59 = 9.59 / 1.59 = 6.031% (approximately 6.0%)
  • eAG (mg/dL) = 7.0 × 18.0182 = 126.1274 mg/dL (approximately 126 mg/dL)

Disclaimer: This calculator provides estimated values based on standard formulas. It should not replace professional medical advice. Always consult with your healthcare provider for diagnosis, treatment, and interpretation of your A1C and blood glucose results.