Enter your HbA1c percentage or estimated average glucose (eAG) to convert between the two values. The A1c Calculator uses the ADA-validated ADAG formula to show your eAG in mg/dL and mmol/L, plus a reference chart of common A1c-to-eAG conversions. Choose your conversion direction — A1c → eAG or eAG → A1c — and get results based on clinically recognized thresholds.
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eAG (mg/dL)
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eAG (mmol/L)
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A1c Category
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A1c, also called HbA1c or glycated hemoglobin, is a blood test that measures the percentage of hemoglobin coated with sugar over the past 2–3 months. Unlike a daily finger-stick glucose test, A1c gives a long-term picture of blood sugar control. It is a primary tool used to diagnose and monitor diabetes and prediabetes.
An A1c below 5.7% is considered normal. A result between 5.7% and 6.4% indicates prediabetes, and 6.5% or above on two separate tests is typically diagnostic of diabetes. For people already managing diabetes, a target of below 7% is commonly recommended, though individual goals should be set with your healthcare provider.
eAG stands for estimated average glucose and expresses your A1c result in the same units (mg/dL or mmol/L) you see on a glucometer. The ADA-validated ADAG formula is: eAG (mg/dL) = 28.7 × A1c (%) − 46.7. This makes it easier to relate your lab A1c to everyday blood sugar readings.
People with well-controlled diabetes typically need an A1c test twice a year. Those whose therapy has changed or who are not meeting glucose targets may need testing every three months. Your doctor will recommend the right frequency based on your individual situation.
Lowering A1c reduces the risk of serious diabetes complications, including kidney disease, nerve damage, vision loss, and cardiovascular problems. Even a modest reduction of 1% can significantly lower the risk of these complications over time, making it one of the most impactful goals in diabetes management.
No. eAG is a mathematical estimate derived from your A1c and reflects average glucose over 2–3 months, including post-meal spikes. A fasting glucose test captures only a single moment in time. The two values complement each other but measure different things.
No. This calculator is for educational and informational purposes only. A diabetes diagnosis requires blood tests performed in a clinical setting, interpreted by a qualified healthcare provider in the context of your full medical history. Always consult your doctor before making any changes to your treatment plan.
eAG is a 2–3 month average and includes all glucose levels — fasting, post-meal, and overnight — weighted by how long you spend at each level. Your daily meter readings are snapshots at specific moments. It is normal for eAG to differ from any individual reading, especially if your glucose varies throughout the day.