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Health Calculator

A1C Calculator.

Estimated Average Glucose (eAG)
154mg/dL
≈ 8.56 mmol/L
A1C7.0%
eAG (mg/dL)154

6.5% or higher — may indicate diabetes range

Educational tool only. Not medical advice. Discuss lab results and targets with your healthcare provider.

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What Is an A1C Calculator?

A1C (HbA1c) reflects your average blood glucose over roughly the past 2–3 months. This free A1C calculator uses the American Diabetes Association (ADA) formula to convert between A1C percentage and estimated average glucose (eAG) in mg/dL or mmol/L.

How to Use This Calculator

  1. Select A1C → eAG to convert a lab result to average glucose, or eAG → A1C for the reverse.
  2. Enter your A1C percentage or glucose value (choose mg/dL or mmol/L).
  3. Read the converted result and reference range indicator.
  4. Discuss your results with a healthcare provider — this tool is for education only.

A1C to eAG Formula

eAG (mg/dL) = 28.7 × A1C − 46.7
A1C = (eAG + 46.7) ÷ 28.7
  • A1C = glycated hemoglobin as a percentage
  • eAG = estimated average glucose in mg/dL
  • mmol/L = eAG (mg/dL) ÷ 18.015

Worked Example

If your A1C is 7.0%: eAG = 28.7 × 7.0 − 46.7 = 200.9 − 46.7 = 154 mg/dL (≈ 8.55 mmol/L). Going the other way: an eAG of 154 mg/dL gives A1C = (154 + 46.7) / 28.7 = 7.0%.

Frequently Asked Questions (FAQs)

How do you convert A1C to average blood sugar?

Using the ADA formula: eAG (mg/dL) = 28.7 × A1C − 46.7. For mmol/L, divide the mg/dL result by 18.015.

What A1C percentage equals 154 mg/dL eAG?

An eAG of 154 mg/dL corresponds to an A1C of about 7.0% using the ADA formula — a common reference in diabetes management discussions with your provider.

Is this A1C calculator for diagnosis?

No. This tool converts between A1C and eAG for educational reference only. Diagnosis and treatment decisions require lab tests interpreted by a healthcare provider.

What is eAG (estimated average glucose)?

eAG translates your A1C into an average daily glucose number in mg/dL or mmol/L — a format most people find easier to understand than a percentage.

How do you convert eAG back to A1C?

A1C = (eAG + 46.7) ÷ 28.7, where eAG is in mg/dL. Multiply mmol/L by 18.015 first if needed.

How do you convert eAG in mmol/L to A1C?

Multiply mmol/L by 18.015 to get mg/dL, then apply A1C = (eAG + 46.7) ÷ 28.7. This calculator handles both units automatically.

Does this calculator store my health data?

No. All conversions run locally in your browser. Your values are never uploaded, saved, or shared.