In brief
Shows what your blood glucose levels have been like over the past two to three months.
What it measures
The amount of haemoglobin in your blood that has glucose attached to it.
Why it is done
To diagnose and monitor type 2 diabetes, and to check how well diabetes management is working.
Reading the results
- 3.5 to 6.0% (15 to 42 mmol/mol): diabetes unlikely.
- 6.1 to 6.4% (43 to 47 mmol/mol): a higher risk of developing diabetes and heart disease.
- 6.5% (48 mmol/mol) or more: diagnostic of diabetes, though the test sometimes needs repeating to confirm the result.
Results are reported as a percentage or in mmol/mol.
Reference ranges
| Result | Range |
|---|---|
| Diabetes unlikely | 3.5 to 6.0 per cent (15 to 42 mmol/mol) |
| Higher risk of diabetes and heart disease | 6.1 to 6.4 per cent (43 to 47 mmol/mol) |
| Diagnostic of diabetes | 6.5 per cent (48 mmol/mol) or more. Sometimes repeated to confirm. |
Ranges differ between laboratories. Always compare a result with the range printed on your own report, and ask your doctor what it means for you.
Before the test
None.
Units. Per cent (NGSP) and mmol/mol (IFCC). Convert with the lab units tool.
What can affect the result
- Anaemia
- Some blood disorders
- Pregnancy
- Iron deficiency
- Chronic kidney disease
- A recent blood transfusion
Related topics
Connections
HbA1c measures
An HbA1c of 6.5% (48 mmol/mol) or more is diagnostic of diabetes.
Source: Pathology Tests Explained, HbA1c
HbA1c shows what your glucose levels have been like over the past two to three months.
Source: Pathology Tests Explained, HbA1c
An HbA1c of 6.1 to 6.4% (43 to 47 mmol/mol) means a higher risk of developing diabetes.
Sources: Pathology Tests Explained, HbA1c; healthdirect Australia, Pre-diabetes
Sources
Test information summarised from the sources listed on this page, read on 12 and 19 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.