Convert HbA1c between mmol/mol (used in the UK) and % (used in the US), see your estimated average glucose, and convert blood sugar readings between mmol/L and mg/dL.

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The formulas

HbA1c conversion table

HbA1c % mmol/mol Average glucose (mmol/L)
5.5 37 6.2
6.0 42 7.0
6.5 48 7.8
7.0 53 8.6
7.5 58 9.4
8.0 64 10.2
9.0 75 11.7
10.0 86 13.3

What HbA1c results mean

Result mmol/mol %
Normal Below 42 Below 6.0
Prediabetes (UK) 42 to 47 6.0 to 6.4
Diabetes 48 or more 6.5 or more

In the US, the American Diabetes Association uses 5.7% to 6.4% for prediabetes. For people with diabetes, a common target is 48 mmol/mol (6.5%) or below, but your diabetes team may set a different target for you.

This converter is for information only and can’t diagnose diabetes. Always discuss results with your GP or diabetes team.

Frequently asked questions

How do I convert HbA1c % to mmol/mol?

Subtract 2.15, then multiply by 10.929. For example, 7% is (7 − 2.15) × 10.929 = 53 mmol/mol.

What is a normal HbA1c?

Below 42 mmol/mol (6.0%) in the UK.

How do I convert mmol/L to mg/dL?

Multiply by 18. So 7 mmol/L is about 126 mg/dL.

What does HbA1c measure?

Your average blood sugar over roughly the last 2 to 3 months.

Sources

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