Health and Fitness Calculators
Estimated A1C
The A1C is an estimate of the glucose in your body over the last 90 days. You can estimate the A1C using your average glucose readings from a continuous glucose machine.
Your estimated A1C is 0, 0.
How it works
A1C reflects roughly the last three months of glucose, weighted toward the most recent weeks. An estimate from an average glucose reading uses the relationship worked out by the A1c-Derived Average Glucose study.
Estimated A1C in percent = (average glucose in mmol/L + 2.59) ÷ 1.59
An average glucose of 7.0 mmol/L, which is 126 mg/dL, gives (7.0 + 2.59) ÷ 1.59, which is 6.0 percent.
The bands
| Estimated A1C | Category |
| Below 5.7 percent | Normal |
| 5.7 to 6.4 percent | Prediabetes |
| 6.5 percent and above | Diabetes |
What this number is not
It is not a laboratory A1C and it is not a diagnosis. A blood test measures what has actually happened to your hemoglobin; this estimates it from the glucose numbers you happen to have recorded.
How accurate it is
The estimate is only as good as the average behind it. Continuous monitor data over 90 days gets close to a laboratory result, while a handful of finger sticks taken at convenient moments does not, because they miss the overnight and after-meal values that move the real figure.
Common questions
How many readings do I need for this to mean anything?
Enough to cover whole days rather than whole weeks. A continuous monitor over three months is ideal. A few readings always taken before breakfast will produce a number, and that number will be wrong.
Does FitnessSyncer estimate this for me?
Yes. The built-in Diabetes report works out your estimated A1C from the glucose readings that have arrived from your connected monitor, alongside your time in range.
Why do my monitor and my laboratory result disagree?
Several things move them apart, including how long your red blood cells live and anemia. A gap of a few tenths of a percent is common and is a question for your doctor rather than a fault in either number.
