A1C to Average Blood Sugar Conversion Chart
Your A1C test result reflects your average blood sugar over the past 2-3 months. Use this chart to understand what your A1C means in terms of daily blood sugar levels.
Quick Reference
The formula used to convert A1C to estimated average glucose (eAG):
eAG (mg/dL) = (28.7 × A1C) - 46.7
Source: Nathan DM, et al. Diabetes Care. 2008. (PMID: 18540046)
Complete Conversion Table
Find your A1C value and see the corresponding estimated average glucose in both mg/dL and mmol/L.
| A1C | eAG (mg/dL) | eAG (mmol/L) | Classification |
|---|---|---|---|
| 5.0% | 97 | 5.4 | Normal |
| 5.5% | 111 | 6.2 | Normal |
| 5.7% | 117 | 6.5 | Prediabetes threshold |
| 6.0% | 126 | 7 | Prediabetes |
| 6.4% | 137 | 7.6 | Prediabetes (upper) |
| 6.5% | 140 | 7.8 | Diabetes threshold |
| 7.0% | 154 | 8.6 | Diabetes |
| 7.5% | 169 | 9.4 | Diabetes |
| 8.0% | 183 | 10.2 | Needs attention |
| 8.5% | 197 | 10.9 | Needs attention |
| 9.0% | 212 | 11.8 | High risk |
| 9.5% | 226 | 12.6 | High risk |
| 10.0% | 240 | 13.4 | Urgent |
| 11.0% | 269 | 14.9 | Urgent |
| 12.0% | 298 | 16.5 | Urgent |
What Your A1C Means
Understanding clinical thresholds and what action to take based on your results.
No intervention needed. Maintain healthy lifestyle.
Lifestyle intervention recommended. Diet, exercise, weight management can often prevent progression.
Current management is working. Continue monitoring.
Discuss with your doctor whether treatment adjustment may help.
Schedule appointment with endocrinologist to review treatment plan.
Urgent medication review needed. Risk of complications increases significantly.
Important Limitations
A1C may be inaccurate in some cases
A1C can give misleading results if you have:
- •Hemoglobin variants: More common in African American, Mediterranean, and Southeast Asian populations. Can cause falsely high or low A1C readings.
- •Iron deficiency anemia: Can falsely elevate A1C results.
- •Recent blood loss or transfusion: Can alter A1C accuracy for 2-3 months after the event.
- •Chronic kidney disease: Advanced kidney disease can affect A1C accuracy.
- •Pregnancy: A1C may not accurately reflect glucose levels during pregnancy.
If your A1C doesn't match your home glucose readings, ask your doctor about a fructosamine test as an alternative. This measures average blood sugar over 2-3 weeks and isn't affected by hemoglobin variants.
Source: ADA Standards of Care 2024, Section 6
A1C vs. Daily Glucose Readings
A1C and daily glucose readings tell different stories about your blood sugar control:
A1C
- • Reflects 2-3 month average
- • Doesn't show daily variations
- • Doesn't reveal glucose spikes
- • Can miss hypoglycemia episodes
Daily Glucose Monitoring
- • Shows current blood sugar
- • Reveals post-meal spikes
- • Catches hypoglycemia
- • Shows day-to-day patterns
Important: Research shows that post-meal glucose spikes above 180 mg/dL are independently associated with cardiovascular risk, even when A1C is at target. Someone with an A1C of 6.8% who regularly spikes to 220 mg/dL after meals may have higher cardiovascular risk than their A1C suggests.
How Often to Test A1C
| Situation | Recommended Frequency |
|---|---|
| Meeting treatment goals, stable control | Every 6 months |
| Not meeting goals or treatment changed | Every 3 months |
| Newly diagnosed diabetes | Every 3 months until stable |
| Prediabetes screening | Annually |
Source: American Diabetes Association Standards of Care, 2024
Want to understand all your lab results?
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