HbA1c Converter
Convert between % and mmol/mol, estimate average glucose.
About this tool
HbA1c is reported in two units globally: percentage (%, the DCCT/NGSP standard used in the US) and mmol/mol (the IFCC standard used in the UK, EU, and most other countries). This tool converts between them and adds an estimated average glucose (eAG).
Diabetes diagnostic thresholds: ≥6.5% (≥48 mmol/mol) is the diabetes range; 5.7–6.4% (39–47 mmol/mol) is prediabetes.
Sources: ADA Standards of Care 2024; Nathan DM et al., Diabetes Care 2008.
Frequently asked questions
What's a good HbA1c target for people with diabetes?
Most adults: <7% (53 mmol/mol). Tighter (<6.5%) is reasonable when achievable without significant hypoglycaemia; looser (<8%) may be appropriate in frailty or limited life expectancy.
Why does my estimated average glucose differ from my meter readings?
eAG is a population average. Meter readings vary by time of day, meals, and stress; CGM (continuous glucose monitoring) gives a more complete picture.
⚕️ Educational only — not a substitute for professional medical advice, diagnosis, or treatment. In an emergency call your local emergency services.