A1C Calculator

Convert an A1C percentage to estimated average blood glucose (eAG) in mg/dL and mmol/L.

Estimated average glucose

117mg/dL

Prediabetes range

In mmol/L: 6.5mmol/L

Estimated average glucose117

Educational estimate only — not medical advice. Talk to a healthcare professional about your health.

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Quick answer

An A1C of 5.7% corresponds to an average glucose of about 117 mg/dL (6.5 mmol/L).

How it works

A1C reflects your average blood sugar over roughly the past three months. This converts it to an estimated average glucose using the formula from the ADAG study.

Formula

eAG (mg/dL) = 28.7 × A1C − 46.7

Assumptions & limitations

Results are rounded for display.

Frequently asked questions

What A1C is normal?

Below 5.7% is considered normal, 5.7–6.4% prediabetes, and 6.5% or above diabetes. Only a clinician can diagnose.