A1C to eAG Calculator
Translate between HbA1c percentages and estimated average glucose (eAG) in a couple of clicks. This calculator applies the American Diabetes Association’s published conversion so you can contextualise lab results with the day-to-day numbers from your glucose meter or CGM.
Educational tool only—consult your healthcare provider before making any changes to medication, diet, or diabetes management plans.
Examples
- Lab result: A1C 7.0% with mode 1 ⇒ Estimated Average Glucose 154 mg/dL (8.6 mmol/L), matching ADA conversion tables.
- Daily monitoring: eAG 160 mg/dL with mode 2 ⇒ Equivalent A1C 7.21%, helping you estimate your next lab trend.
- Tight control: A1C 6.2% with mode 1 ⇒ 131 mg/dL (7.3 mmol/L), showing the benefit of sustained glucose management.
FAQ
Which value should I enter in mode 1?
Enter the HbA1c percentage from your lab report—for example 7.0. The calculator then outputs an estimated average glucose in mg/dL and mmol/L.
How do I prepare a value for mode 2?
Take the mean of your glucose readings (in mg/dL) over several weeks, or use the average reported by your continuous glucose monitor. Input that number to estimate the corresponding A1C.
Does this replace medical advice?
No. It’s an educational approximation. Always discuss target ranges and treatment decisions with your healthcare team, especially if you have anaemia, pregnancy, or other conditions that change red blood cell turnover.
Why might my meter average differ from lab results?
A1C reflects roughly three months of glucose exposure weighted toward recent weeks, while a home meter average depends on how often and when you test. Factors like red blood cell lifespan and CGM calibration can also cause differences.
Additional Information
- The ADA formula links the two metrics: eAG (mg/dL) = 28.7 × A1C − 46.7. Divide mg/dL by 18.0182 to convert to mmol/L.
- Use mode 1 when you have a laboratory HbA1c percentage and want to estimate what it represents in daily glucose values.
- Use mode 2 when you average glucose readings from a meter or CGM and want to anticipate how that trend might show up in your next A1C test.
- Typical general targets for adults with diabetes are A1C below 7% and eAG below 154 mg/dL, but always confirm personalised goals with your clinician.