HbA1c Calculator
Convert HbA1c (%) to estimated average glucose in mg/dL and mmol/L — or glucose back to HbA1c — with IFCC mmol/mol and the ADA normal, prediabetes and diabetes ranges.
Input
In the unit chosen above.
Output
Reference conversion, not medical advice. eAG is a population-level estimate; individual meter readings can differ. Talk to a clinician about your results.
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/hba1c-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"mode": "a1c",
"value": "7"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `hba1c-calculator` tool (HbA1c Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/hba1c-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="HbA1c Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
HbA1c (glycated haemoglobin) reflects your average blood sugar over roughly the last three months. Labs report it as a percentage or in IFCC units (mmol/mol), while home meters report glucose in mg/dL or mmol/L. This calculator converts between them.
How to use it
- Choose what you have: HbA1c (%), average glucose in mg/dL, or average glucose in mmol/L.
- Enter the value.
- Read the HbA1c, IFCC mmol/mol, estimated average glucose (eAG) in both units, and the ADA category.
The formulas
- eAG (mg/dL) = 28.7 × HbA1c − 46.7 (the ADAG study fit adopted by the American Diabetes Association)
- mg/dL ÷ 18.016 = mmol/L
- IFCC (mmol/mol) = (HbA1c − 2.15) × 10.929
ADA ranges
| HbA1c | Category |
|---|---|
| Below 5.7% | Normal |
| 5.7% – 6.4% | Prediabetes |
| 6.5% or higher | Diabetes range |
eAG is a population-level estimate; your own meter readings can differ. This is a reference conversion, not medical advice — talk to a clinician about your results. Everything runs in your browser.