Hemoglobin A1c Calculation

Hemoglobin A1c to eAG Converter

function calculateA1c() { var a1cInput = document.getElementById("a1cValue").value; var a1c = parseFloat(a1cInput); if (isNaN(a1c) || a1c 15) { document.getElementById("eagResult").innerHTML = "Please enter a valid A1c percentage (e.g., 4.0 – 15.0)."; return; } // Formula: eAG (mg/dL) = 28.7 * HbA1c (%) – 46.7 var eag_mgdl = (28.7 * a1c) – 46.7; // Formula: eAG (mmol/L) = 1.59 * HbA1c (%) – 2.59 var eag_mmol = (1.59 * a1c) – 2.59; document.getElementById("eagResult").innerHTML = "" + eag_mgdl.toFixed(2) + " mg/dL (or " + eag_mmol.toFixed(2) + " mmol/L)"; } .calculator-container { background-color: #f9f9f9; border: 1px solid #ddd; border-radius: 8px; padding: 20px; max-width: 600px; margin: 20px auto; font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; box-shadow: 0 4px 8px rgba(0,0,0,0.05); } .calculator-container h2 { color: #333; text-align: center; margin-bottom: 20px; font-size: 1.8em; } .calculator-content { display: flex; flex-direction: column; gap: 15px; } .input-group { display: flex; flex-direction: column; margin-bottom: 10px; } .input-group label { margin-bottom: 5px; color: #555; font-weight: bold; } .input-group input[type="number"] { padding: 10px; border: 1px solid #ccc; border-radius: 5px; font-size: 1em; width: 100%; box-sizing: border-box; } .calculator-container button { background-color: #007bff; color: white; padding: 12px 20px; border: none; border-radius: 5px; cursor: pointer; font-size: 1.1em; transition: background-color 0.3s ease; width: 100%; box-sizing: border-box; } .calculator-container button:hover { background-color: #0056b3; } .result-group { margin-top: 20px; padding: 15px; background-color: #e9f7ef; border: 1px solid #d4edda; border-radius: 5px; text-align: center; } .result-group h3 { color: #28a745; margin-top: 0; margin-bottom: 10px; font-size: 1.3em; } .calculator-result { font-size: 1.4em; color: #333; font-weight: bold; } .calculator-result strong { color: #0056b3; }

Understanding Your Hemoglobin A1c and Estimated Average Glucose (eAG)

The Hemoglobin A1c (HbA1c) test is a crucial blood test used to diagnose and monitor diabetes. Unlike daily blood glucose readings, which show your sugar levels at a specific moment, the A1c test provides an average of your blood glucose over the past two to three months. This is because it measures the percentage of hemoglobin (a protein in red blood cells) that is coated with sugar (glycated).

Why is HbA1c Important?

• Long-term Glucose Control: It gives a broader picture of how well your blood sugar is being managed over time, rather than just daily fluctuations.
• Diabetes Diagnosis: An A1c level of 6.5% or higher is typically indicative of diabetes.
• Prediabetes Identification: An A1c between 5.7% and 6.4% suggests prediabetes, indicating a higher risk of developing type 2 diabetes.
• Risk Assessment: Higher A1c levels are associated with a greater risk of diabetes complications, such as heart disease, kidney disease, nerve damage, and eye problems.

What is Estimated Average Glucose (eAG)?

While HbA1c is expressed as a percentage, many people are more familiar with blood glucose readings in mg/dL (milligrams per deciliter) or mmol/L (millimoles per liter). Estimated Average Glucose (eAG) is a term used to translate your A1c percentage into the same units you see on your home blood glucose meter. This makes it easier to understand what your A1c result means in terms of your daily average blood sugar levels.

How is eAG Calculated from HbA1c?

The conversion from HbA1c to eAG is based on a standardized formula. Our calculator uses the following widely accepted formulas:

• eAG (mg/dL) = 28.7 × HbA1c (%) – 46.7
• eAG (mmol/L) = 1.59 × HbA1c (%) – 2.59

These formulas allow for a direct conversion, helping you relate your long-term A1c result to the more familiar daily glucose numbers.

Interpreting Your Results

Here's a general guide to interpreting HbA1c and eAG values:

• Normal: HbA1c below 5.7% (eAG below 117 mg/dL or 6.5 mmol/L)
• Prediabetes: HbA1c 5.7% to 6.4% (eAG 117-137 mg/dL or 6.5-7.6 mmol/L)
• Diabetes: HbA1c 6.5% or higher (eAG 140 mg/dL or 7.8 mmol/L and above)

For individuals with diagnosed diabetes, the target A1c is often below 7.0% (eAG below 154 mg/dL or 8.6 mmol/L), but this can vary based on individual health conditions, age, and other factors. Always discuss your A1c and eAG results with your healthcare provider to understand what they mean for your specific health management plan.

Example Calculation:

Let's say your Hemoglobin A1c test result is 7.0%.

• Using the formula for mg/dL: eAG = (28.7 × 7.0) – 46.7 = 200.9 – 46.7 = 154.2 mg/dL
• Using the formula for mmol/L: eAG = (1.59 × 7.0) – 2.59 = 11.13 – 2.59 = 8.54 mmol/L

This means an A1c of 7.0% corresponds to an estimated average blood glucose level of approximately 154 mg/dL or 8.54 mmol/L over the past 2-3 months. Use the calculator above to quickly convert your own A1c values.