A1C Calculator
Use this a1c calculator to convert an A1C percentage to estimated average glucose, or enter average glucose to estimate A1C in both common units.
Result
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Result
— A1C
- Estimated average glucose
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- Glucose in mmol/L
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- Published A1C range
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- IFCC equivalent
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| A1C | mg/dL | mmol/L |
|---|
Context only. This reports ranges, not a diagnosis, treatment or target.
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How the A1C calculator works
This a1c calculator uses the American Diabetes Association ADAG equation to convert an A1C percentage into estimated average glucose (eAG), or to estimate A1C from an average glucose value.
The result shows glucose in mg/dL and mmol/L, plus the published A1C range it falls in: normal, prediabetes or diabetes range. These are ranges, not a diagnosis or a personal treatment target.
eAG is an estimate from a population regression. A1C can be misleading with anaemia, haemoglobin variants, recent transfusion, pregnancy or a shortened red-cell lifespan.
eAG (mg/dL) = 28.7 × A1C − 46.7; A1C = (eAG + 46.7) ÷ 28.7; eAG (mmol/L) = eAG (mg/dL) ÷ 18.0182 The A1C target is set with a clinician and is not the same for everyone. IFCC units (mmol/mol) are a different scale.
A1C calculator FAQ
What does an A1C calculator show?
It estimates average glucose from an A1C percentage, or estimates A1C from average glucose. It also shows both glucose units and a published range.
Is the result a diagnosis?
No. The calculator reports ranges only. Diagnosis and interpretation require appropriate clinical testing and a clinician's judgment.
Why can A1C be misleading?
Anaemia, haemoglobin variants, a recent transfusion, pregnancy and a shortened red-cell lifespan can affect how A1C reflects glucose.
Are IFCC units the same as A1C percentage?
No. IFCC mmol/mol is a different scale. This tool includes an approximate IFCC equivalent as a secondary output.
What A1C target should I use?
A target is set with a clinician and is not the same for everyone. This calculator does not provide a target or treatment advice.