Health & Wellness

HbA1c Calculator

Convert your HbA1c percentage to estimated average glucose (eAG).

Enter your HbA1c percentage from a recent blood test to calculate your estimated average blood glucose level over the past 2-3 months, using the standard ADA-recognized formula.

Enter a valid HbA1c percentage.

Estimated Average Glucose

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How to Use This Tool

  1. Enter your HbA1c percentage from your lab test report.
  2. Click Calculate eAG to see your estimated average glucose level over the past 2-3 months.

The HbA1c to eAG Formula

The American Diabetes Association (ADA) recognizes a standard formula to convert HbA1c (glycated haemoglobin, a measure reflecting average blood sugar over roughly 2-3 months) into an estimated Average Glucose (eAG), expressed in the same units (mg/dL) as a regular blood glucose reading:

eAG (mg/dL) = 28.7 × HbA1c(%) − 46.7

HbA1c Classification Ranges

Why eAG Is Useful

Many patients find it easier to interpret their glucose control in the familiar mg/dL units they see on a glucometer, rather than as an abstract HbA1c percentage. eAG bridges this gap, giving a more intuitive sense of average blood sugar levels.

Important Medical Note

HbA1c and eAG reflect average glucose over months, not a single point-in-time reading, and can be affected by certain conditions (like anemia or hemoglobin variants) that don't reflect true glucose control. Always discuss your results with a healthcare professional for proper interpretation and management.

Frequently Asked Questions

What is a normal HbA1c level?

According to the ADA, an HbA1c below 5.7% is considered normal, 5.7%–6.4% indicates prediabetes, and 6.5% or above indicates diabetes.

Is eAG the same as a fasting blood sugar reading?

No, eAG represents your estimated average glucose over the past 2-3 months, while a fasting blood sugar test measures your glucose level at a single point in time — they measure different things and can differ.

Can certain conditions affect HbA1c accuracy?

Yes, conditions like anemia, certain hemoglobin variants, and some chronic kidney or liver conditions can affect HbA1c accuracy, which is why it should always be interpreted alongside other clinical information by a healthcare professional.

This calculator is provided for general informational and estimation purposes only. Results should not be treated as professional financial, tax, legal, medical, or engineering advice. Always verify critical calculations with a qualified professional or official source before making decisions.