A1c Blood Sugar Calculator

A1C to Blood Sugar Converter

Use this tool to convert your A1C percentage to estimated average glucose (eAG) in mg/dL or mmol/L, and vice-versa.

A1C to eAG

Estimated Average Glucose (eAG):

mg/dL: –

mmol/L: –

eAG (mg/dL) to A1C

Estimated A1C: – %

eAG (mmol/L): –

eAG (mmol/L) to A1C

Estimated A1C: – %

eAG (mg/dL): –

function calculateA1CtoeAG() { var a1c = parseFloat(document.getElementById('a1cInput').value); if (isNaN(a1c) || a1c < 0) { document.getElementById('eagMgdlResult').textContent = 'Invalid Input'; document.getElementById('eagMmolResult').textContent = 'Invalid Input'; return; } // Formula: eAG (mg/dL) = (28.7 * A1C) – 46.7 var eagMgdl = (28.7 * a1c) – 46.7; // Formula: eAG (mmol/L) = (1.59 * A1C) – 2.59 var eagMmol = (1.59 * a1c) – 2.59; document.getElementById('eagMgdlResult').textContent = eagMgdl.toFixed(1); document.getElementById('eagMmolResult').textContent = eagMmol.toFixed(1); } function calculateEagMgdlToA1C() { var eagMgdl = parseFloat(document.getElementById('eagMgdlInput').value); if (isNaN(eagMgdl) || eagMgdl < 0) { document.getElementById('a1cResultMgdl').textContent = 'Invalid Input'; document.getElementById('eagMmolResultFromMgdl').textContent = 'Invalid Input'; return; } // Formula: A1C = (eAG (mg/dL) + 46.7) / 28.7 var a1c = (eagMgdl + 46.7) / 28.7; // Convert mg/dL to mmol/L: mmol/L = mg/dL / 18 var eagMmol = eagMgdl / 18; document.getElementById('a1cResultMgdl').textContent = a1c.toFixed(1); document.getElementById('eagMmolResultFromMgdl').textContent = eagMmol.toFixed(1); } function calculateEagMmolToA1C() { var eagMmol = parseFloat(document.getElementById('eagMmolInput').value); if (isNaN(eagMmol) || eagMmol < 0) { document.getElementById('a1cResultMmol').textContent = 'Invalid Input'; document.getElementById('eagMgdlResultFromMmol').textContent = 'Invalid Input'; return; } // Formula: A1C = (eAG (mmol/L) + 2.59) / 1.59 var a1c = (eagMmol + 2.59) / 1.59; // Convert mmol/L to mg/dL: mg/dL = mmol/L * 18 var eagMgdl = eagMmol * 18; document.getElementById('a1cResultMmol').textContent = a1c.toFixed(1); document.getElementById('eagMgdlResultFromMmol').textContent = eagMgdl.toFixed(1); } // Initial calculation on load for default values window.onload = function() { calculateA1CtoeAG(); calculateEagMgdlToA1C(); calculateEagMmolToA1C(); };

Understanding A1C and Estimated Average Glucose (eAG)

The A1C test, also known as the hemoglobin A1C or HbA1c test, is a common blood test used to diagnose type 1 and type 2 diabetes and to monitor how well you're managing your diabetes. It measures your average blood sugar levels over the past two to three months.

What is A1C?

Hemoglobin is a protein in your red blood cells that carries oxygen. When glucose (sugar) enters your bloodstream, it attaches to hemoglobin. The A1C test measures the percentage of your hemoglobin that is coated with sugar (glycated). Since red blood cells live for about three months, the A1C test provides a good long-term picture of your blood sugar control.

• 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 that converts your A1C test result into a number that is more familiar to people with diabetes: an average blood glucose level, similar to what you'd see on a home blood glucose meter. It can be expressed in milligrams per deciliter (mg/dL), commonly used in the United States, or millimoles per liter (mmol/L), used in many other countries.

The eAG provides a direct correlation to your A1C, making it easier to understand the implications of your A1C result in terms of daily blood sugar readings.

Why Convert Between A1C and eAG?

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

• Better Understanding: Many people find it easier to relate to an average blood sugar number (eAG) than a percentage (A1C).
• Comparing Results: It allows you to compare your long-term A1C results with your daily blood glucose meter readings.
• Goal Setting: Healthcare providers often set A1C goals, and knowing the equivalent eAG can help you understand what daily blood sugar levels you should aim for.

The Formulas Used

The conversions in this calculator are based on established formulas:

• A1C to eAG (mg/dL): eAG (mg/dL) = (28.7 × A1C) - 46.7
• A1C to eAG (mmol/L): eAG (mmol/L) = (1.59 × A1C) - 2.59
• eAG (mg/dL) to A1C: A1C = (eAG (mg/dL) + 46.7) / 28.7
• eAG (mmol/L) to A1C: A1C = (eAG (mmol/L) + 2.59) / 1.59

These formulas provide a close estimate and are widely accepted for clinical use.

Examples of A1C and eAG Conversions

Let's look at some common scenarios:

• A1C of 5.0%: This is a normal A1C.
  • eAG (mg/dL) = (28.7 * 5.0) – 46.7 = 143.5 – 46.7 = 96.8 mg/dL
  • eAG (mmol/L) = (1.59 * 5.0) – 2.59 = 7.95 – 2.59 = 5.36 mmol/L
• A1C of 6.5%: This indicates diabetes.
  • eAG (mg/dL) = (28.7 * 6.5) – 46.7 = 186.55 – 46.7 = 139.85 mg/dL
  • eAG (mmol/L) = (1.59 * 6.5) – 2.59 = 10.335 – 2.59 = 7.745 mmol/L
• A1C of 8.0%: This suggests less controlled diabetes.
  • eAG (mg/dL) = (28.7 * 8.0) – 46.7 = 229.6 – 46.7 = 182.9 mg/dL
  • eAG (mmol/L) = (1.59 * 8.0) – 2.59 = 12.72 – 2.59 = 10.13 mmol/L

These examples demonstrate how a higher A1C percentage directly correlates to higher estimated average glucose levels.

Important Disclaimer

This calculator is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult with your healthcare provider for any health concerns or before making any decisions related to your health or treatment.