Free tool
mg/dL ↔ mmol/L
Blood glucose unit converter. Type in either box. Runs in your browser; nothing is sent anywhere.
The factor
1 mmol/L = 18.0156 mg/dL, because a mole of glucose weighs 180.156 g. To go from mg/dL to mmol/L, divide by 18; to go back, multiply by 18. The rounded 18 is fine by hand; this page, Glide, Nightscout and xDrip use the full 18.01559 so that a stored mg/dL value and its displayed mmol/L value round the same way everywhere.
Common thresholds in both units
| What | mg/dL | mmol/L |
|---|---|---|
| Very low (level 2 hypoglycemia) | below 54 | below 3.0 |
| Low | 54–69 | 3.0–3.8 |
| In range | 70–180 | 3.9–10.0 |
| A perfect 100 | 100 | 5.6 |
| High | 181–250 | 10.1–13.9 |
| Very high | above 250 | above 13.9 |
| Typical sensor ceiling | 400 | 22.2 |
The bands are the ones in the 2019 international consensus on CGM metrics, which publishes them in both units. The boundaries do not convert exactly (181 mg/dL is 10.05 mmol/L); the mmol/L column uses the consensus figures, and Glide uses the same ones when it shows a band in mmol/L.
Which unit is which
The US uses mg/dL. The UK, Canada, Australia and most of Europe use mmol/L. Both describe the same amount of glucose in blood; mmol/L counts molecules and mg/dL counts mass. A CGM app usually shows the unit that matches the phone's region. In Glide the unit is a setting per account (Settings → Display), so a parent in the UK and a grandparent in the US can follow the same profile and each read it in their own unit.