Convert your HbA1c percentage to estimated average blood glucose (eAG). Works in both mg/dL (US) and mmol/L (international). Enter an A1C or an average glucose — this calculator converts both ways.
| A1C (%) | eAG (mg/dL) | eAG (mmol/L) | Classification |
|---|---|---|---|
| Below 5.7% | Below 117 | Below 6.5 | ✅ Normal |
| 5.7% – 6.4% | 117 – 137 | 6.5 – 7.6 | ⚠️ Prediabetes |
| 6.5% – 7.9% | 140 – 183 | 7.8 – 10.2 | 🔴 Diabetes (at diagnosis / controlled) |
| 8.0% and above | 183+ | 10.2+ | 🔴 Diabetes (needs attention) |
Source: American Diabetes Association (ADA) standards. Most adults with diabetes aim for an A1C below 7.0%. Your personal target may differ based on age, comorbidities, and your doctor's guidance.
The American Diabetes Association's conversion formula is: eAG (mg/dL) = 28.7 × A1C − 46.7. To convert to mmol/L, divide by 18.018.
This formula was derived from the ADAG (A1c Derived Average Glucose) study, which tracked continuous glucose monitoring data against lab-measured A1C in over 500 people with and without diabetes. It replaced older, less accurate conversion tables.
Hemoglobin A1c (HbA1c) measures the percentage of hemoglobin molecules in your red blood cells that have glucose attached to them (glycated hemoglobin). Because red blood cells live about 3 months, A1C reflects your average blood sugar over the past 2–3 months — not just what it was the morning you had your blood drawn. That's why it's much more useful than a single fasting glucose reading for assessing overall blood sugar control.
Regular physical activity improves insulin sensitivity, which directly lowers A1C over time. Studies show that consistent aerobic exercise can reduce A1C by 0.6–0.8 percentage points in people with type 2 diabetes — comparable to adding a second oral medication. Resistance training also improves glucose disposal into muscle tissue. If you're tracking A1C, pairing it with tools like our Calorie Burn Calculator can help you build the exercise habits that move the needle.
A normal A1C for adults without diabetes is below 5.7%, corresponding to an average blood sugar of roughly 117 mg/dL (6.5 mmol/L). An A1C between 5.7% and 6.4% indicates prediabetes. At 6.5% or above on two separate tests, a diabetes diagnosis is typically made by current ADA guidelines.
The most evidence-backed lifestyle approaches are regular aerobic exercise (150+ minutes per week at moderate intensity), reducing refined carbohydrate and added sugar intake, losing excess body weight, improving sleep quality, and managing stress. These work through different mechanisms but all reduce average blood glucose over time. Medication changes are a clinical decision — discuss with your doctor.
People without diabetes and at low risk typically get tested every 3 years as part of routine screening. Those with prediabetes are often tested annually. People with diabetes typically test every 3 months if not at goal, or every 6 months once stable and well-controlled.
Yes. Conditions that affect red blood cell lifespan can cause A1C to be falsely high or low. These include hemolytic anemia, iron deficiency anemia, sickle cell disease, recent blood transfusion, certain hemoglobin variants, and kidney disease. If your A1C doesn't match your daily glucose readings, ask your doctor whether an alternative glycemic marker (like fructosamine) might be more appropriate.
Not exactly — A1C is a percentage reflecting glycated hemoglobin, while blood sugar is a direct measure of glucose concentration in your blood at a point in time. This calculator converts between the two using the ADA's validated ADAG formula, but they measure different things. Daily blood sugar can spike and drop dramatically; A1C smooths all of that out into a 3-month average.
For most non-pregnant adults with diabetes, the ADA recommends an A1C below 7.0%. For younger, healthier patients without significant comorbidities, a lower target (below 6.5%) may be appropriate. For older adults with complex health conditions or a high risk of hypoglycemia, a higher target (below 8.0%) may be safer. Your individual target should always be set with your healthcare provider.