Free · No signup · Updated October 2026
A1c calculator: glucose to A1c and back
An A1c of 7% means an average glucose of about 154 mg/dL (8.6 mmol/L) over the past two to three months. Type either number and the other one converts, using the formula the American Diabetes Association uses.
- Best for converting a lab result
- Free, no account, no email
- Updates as you type
- Shows the formula it uses
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How do you convert glucose to A1c?
Average glucose in mg/dL = 28.7 × A1c − 46.7. To go the other way, A1c = (average glucose + 46.7) ÷ 28.7. The formula comes from the A1c-Derived Average Glucose study (Nathan, Diabetes Care, 2008), which compared A1c with continuous glucose readings in 507 adults.
| A1c | Average glucose | mmol/L |
|---|---|---|
| 5% | 97 mg/dL | 5.4 |
| 5.7% | 117 mg/dL | 6.5 |
| 6% | 125 mg/dL | 7.0 |
| 6.5% | 140 mg/dL | 7.8 |
| 7% | 154 mg/dL | 8.6 |
| 8% | 183 mg/dL | 10.2 |
| 9% | 212 mg/dL | 11.7 |
| 10% | 240 mg/dL | 13.3 |
What do the A1c ranges mean?
The American Diabetes Association reads below 5.7% as normal, 5.7 to 6.4% as prediabetes and 6.5% or higher as diabetes. Your own goal belongs with your clinician; many adults with diabetes aim for under 7%.
An average hides the swings. Two people at 6% can live very different days, which is why the meals behind the number matter.
Which everyday plates carry the most added sugar?
Added sugar is the part of a meal people most often change first. These six plates carry the most in Cloche’s food data. Whole fruit and plain milk don’t count as added sugar.
| Plate | Portion | Estimated added sugar | Of 20 g reference |
|---|---|---|---|
| Blueberry Pancakes | 3 pancakes, maple syrup | 52 g | 258% |
| Waffle | 1 waffle, syrup | 30 g | 150% |
| Cheesecake | 1 slice | 25 g | 124% |
| Blueberry Muffin | 1 muffin | 24 g | 118% |
| Ice Cream | 1 scoop | 17 g | 84% |
| Granola with Yogurt | 1 bowl | 16 g | 80% |
For the whole day, not one meal, see Cloche for blood sugar. More free tools: the fiber calculator and the sodium calculator. Every number is an estimate; we publish how far off the estimates run against USDA reference foods.
Questions people ask
What is an A1c of 7 in average glucose?
About 154 mg/dL, or 8.6 mmol/L, using the formula average glucose = 28.7 × A1c − 46.7.
What A1c is normal?
Below 5.7% is normal. 5.7 to 6.4% is prediabetes, and 6.5% or higher on two tests is diabetes, by the American Diabetes Association’s ranges.
How accurate is this conversion?
It is an average from a study of 507 adults. For an A1c of 7%, the study’s 95% range ran from 123 to 185 mg/dL, so your own average can sit well away from the formula.
How long does it take A1c to change?
A1c reflects about the last two to three months, with the most recent month weighing most. Labs usually repeat it every three months.
See which meals carried the sugar
Cloche is a food journal for iPhone. Say what you ate or take a photo, and it reads each meal for added sugar, fiber and protein, then shows which ones carried the most this week.
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