HbA1c to Average Glucose Calculator (eAG, % and mmol/mol)
Estimated average blood glucose from an HbA1c result, with the value in both % and mmol/mol and the ADA category.
Results
The dashed line marks the value you entered.
What this tool does
HbA1c reflects the average blood glucose of roughly the last two to three months, weighted towards the most recent weeks. The ADAG study, published in 2008, found a straight-line link between it and measured average glucose: eAG in mg/dL = 28.7 × HbA1c − 46.7, so 7 % corresponds to about 154 mg/dL (8.6 mmol/L). The two reporting units are linked by the IFCC master equation, which is why a lab in Portugal or the UK quoting 53 mmol/mol is the same as 7 % in the US. The ADA bands shown, 5.7 % and 6.5 %, are screening thresholds only, and HbA1c can be misleading in anaemia, after blood loss or transfusion, and with some haemoglobin variants.
Formula
eAG (mg/dL) = 28.7 × HbA1c − 46.7 · eAG (mmol/L) = eAG ÷ 18.016 · IFCC (mmol/mol) = 10.929 × (HbA1c % − 2.15)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
av | Your HbA1c | — |
un | Unit of the HbA1c | — |
EA | Estimated average glucose (eAG) | mg/dL |
EM | The same in mmol/L | mmol/L |
PC | HbA1c in % | % |
IF | HbA1c in mmol/mol | mmol/mol |
CT | ADA category | — |
Worked example
- Your HbA1c6.5
- Unit of the HbA1c1
- Estimated average glucose (eAG)140 mg/dL
- The same in mmol/L7.8 mmol/L
- HbA1c in %6.5 %
- HbA1c in mmol/mol48 mmol/mol
- ADA category6.5 % (48 mmol/mol) or more — diabetes range
Limitations
- This tool is informational only. It does not diagnose, treat or replace a qualified health professional. Speak to a doctor before making decisions about your health.
- For work that must comply with a standard or be signed off, check the result against the applicable code and have it reviewed by a qualified engineer.