HbA1c to average glucose calculator
HbA1c reflects your average blood sugar over about three months. This converts it to an estimated average glucose, the same units your meter shows, so the number feels concrete. Enter an A1C, or work backwards from an average glucose.
An estimate from the ADAG regression, not a diagnosis. A lab A1C and a meter reading measure different things. Talk to your clinician about your numbers.
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The formula
The conversion comes from the A1c-Derived Average Glucose (ADAG) study, which defined the relationship between A1C and average glucose:
- eAG (mg/dL) = 28.7 × A1C − 46.7
- eAG (mmol/L) = 1.59 × A1C − 2.59
Worked example: an A1C of 6.0 percent gives 28.7 × 6.0 − 46.7, about 126 mg/dL (7.0 mmol/L). An A1C of 7.0 percent works out to about 154 mg/dL.
How carb fasting fits
Because HbA1c tracks roughly three months of blood sugar, it is a useful way to see whether an eating change is moving your average over time. It misses day-to-day swings; a CGM is better for those. See the HbA1c page for the cut points and what they mean, or read the plan.
References
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