An A1C average blood sugar chart converts your A1C percentage into an estimated average glucose (eAG) in mg/dL. The conversion uses the American Diabetes Association formula eAG = 28.7 × A1C − 46.7. For example, an A1C of 5.7% equals roughly 117 mg/dL, and an A1C of 6.5% equals about 140 mg/dL. The chart makes it easier to compare your lab A1C with the readings from your home glucose meter.
The Complete A1C Average Blood Sugar Chart
| A1C (%) | eAG (mg/dL) | eAG (mmol/L) | Category |
|---|---|---|---|
| 4.0% | 68 | 3.8 | Low normal |
| 4.5% | 82 | 4.6 | Normal |
| 5.0% | 97 | 5.4 | Normal |
| 5.3% | 105 | 5.9 | Normal |
| 5.5% | 111 | 6.2 | Normal |
| 5.7% | 117 | 6.5 | Prediabetes (lower edge) |
| 6.0% | 126 | 7.0 | Prediabetes |
| 6.2% | 131 | 7.3 | Prediabetes |
| 6.4% | 137 | 7.6 | Prediabetes (upper edge) |
| 6.5% | 140 | 7.8 | Diabetes |
| 7.0% | 154 | 8.6 | Diabetes — standard goal |
| 7.5% | 169 | 9.4 | Diabetes — elevated |
| 8.0% | 183 | 10.2 | Diabetes — elevated |
| 9.0% | 212 | 11.8 | Diabetes — uncontrolled |
| 10.0% | 240 | 13.4 | Diabetes — uncontrolled |
| 11.0% | 269 | 14.9 | Diabetes — urgent attention |
For more detail on any specific A1C range, see our A1C levels guide.
How the Conversion Formula Works
The formula was established by a multinational study led by Dr. David Nathan and published in Diabetes Care in 2008. Researchers correlated A1C values with thousands of self-monitored glucose readings from subjects with and without diabetes.
The American Diabetes Association officially endorses this formula. The result (eAG) is meant to be directly comparable to the values on your home glucose meter, which are typically reported in mg/dL (US) or mmol/L (most other countries).
What Your A1C Blood Sugar Number Means
Normal (below 5.7% / below 117 mg/dL)
Average glucose in the healthy range. Continue balanced eating, physical activity, and periodic screening.
Prediabetes (5.7-6.4% / 117-137 mg/dL)
Your pancreas is working overtime to keep up. Untreated, about 15-30% of people progress to type 2 diabetes within 5 years. The good news: prediabetes is reversible through diet, exercise, and weight loss.
Diabetes (6.5% or higher / 140+ mg/dL)
Meets the criteria for type 2 diabetes (usually confirmed with a repeat test). Active management — often including metformin or other medication alongside lifestyle changes — is recommended to prevent complications.
Why eAG Doesn’t Always Match Your Home Meter
If your home meter shows an average of 135 mg/dL but your A1C-derived eAG is 117 mg/dL, don’t panic — there are common explanations:
- Meter timing bias: If you only test fasting or post-meal, your sample is skewed.
- Meter accuracy: Home meters have roughly ±15% variability.
- Individual glycation rate: Some people glycate hemoglobin faster or slower than average.
- Red blood cell lifespan: Shorter lifespan (hemolytic anemia) lowers A1C; longer lifespan raises it.
- Hemoglobin variants: Can cause lab-specific A1C interference.
A continuous glucose monitor (CGM) provides 1,440 readings per day, making its average far more representative than a handful of finger-sticks. If you use a CGM, compare your 90-day average glucose to the A1C-derived eAG.
Using the Chart to Set Goals
Translating A1C to mg/dL can make goals feel more tangible. Instead of “get A1C from 6.4% to 5.6%,” try:
- “Lower average glucose from 137 mg/dL to 114 mg/dL”
- “Aim for post-meal glucose under 140 mg/dL”
- “Keep fasting glucose under 100 mg/dL”
These daily targets — trackable on a meter or CGM — naturally drive A1C down over 2-3 months.
Practical Steps to Move Down the Chart
- Eat meals with fiber and protein first. Slows glucose absorption.
- Walk for 10-15 minutes after meals. Reduces post-meal spikes.
- Cut sugary drinks and refined flour. Biggest levers for most people.
- Prioritize sleep. Poor sleep raises next-day glucose.
- Manage stress. Cortisol raises blood sugar over time.
- Lose 5-7% of body weight. If applicable, major effect on insulin sensitivity.
Most people can lower A1C 0.5 to 2.0 points (roughly 15-60 mg/dL average glucose) within 3-6 months using these strategies.
The Bottom Line
The A1C average blood sugar chart turns a percentage into a mg/dL number your glucose meter can relate to. Normal average glucose is below 117 mg/dL (A1C below 5.7%); prediabetes is 117-137 mg/dL (5.7-6.4%); diabetes starts at 140 mg/dL (6.5%). Use the chart to understand your lab results, set daily glucose targets, and track progress alongside a home meter or CGM. If your number places you in the prediabetes range, now is the best time to intervene — small sustained changes can move you back into the normal zone within months.
