HbA1c to Average Glucose Calculator
Enter your HbA1c percentage to see what it means as an estimated average blood glucose - in both mg/dL and mmol/L.
Educational estimator only - not medical advice.
Typical lab range: 4-15% * Normal: below 5.7% * Diabetes: 6.5% and above
Enter your HbA1c percentage above to see your estimated average glucose.
This calculator uses the ADAG (A1c-Derived Average Glucose) formula, validated across a broad population by the American Diabetes Association:
The ADAG study enrolled 507 participants across 10 international sites, collecting continuous glucose monitoring data alongside lab HbA1c measurements over 3 months. The resulting equation is the most widely validated method for translating an HbA1c into a daily glucose equivalent.
Why this matters day-to-day: HbA1c as a percentage is abstract - knowing that a 7.0% A1c corresponds to roughly 154 mg/dL (8.6 mmol/L) makes it tangible and relatable to your meter or CGM readings.
The 90-day window: HbA1c reflects glucose attached to red blood cells over their ~90-day lifespan. Recent weeks contribute more than earlier weeks - the last 30 days account for roughly 50% of the result.
Important: eAG is a population-level estimate. Individual variation means your personal correlation between A1c and daily average may differ. Consult your healthcare provider for personalised interpretation.
Understand the full story of HbA1c - what it measures, why it matters, its limitations, and how to use it alongside time-in-range and daily glucose data for smarter diabetes management.
FOD Starter: Ch 5 - The A1cThis calculator is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider or a qualified diabetes educator regarding your personal health and any changes to your management plan. Individual results may vary.