How to convert blood sugar units
Blood glucose is measured in two units depending on the country: mg/dL, used in the US and some others, and mmol/L, used in the UK and much of the world. This converter switches between them instantly, which is handy for comparing readings, apps or advice that use different units.
The formula
mmol/L = mg/dL / 18, and mg/dL = mmol/L x 18.
Worked example
A reading of 100 mg/dL is about 5.55 mmol/L. A reading of 7 mmol/L is about 126 mg/dL.
mg/dL to mmol/L conversion table
The exact conversion is mmol/L = mg/dL ÷ 18 (and mg/dL = mmol/L × 18). These are the readings people look up most often:
| mg/dL | mmol/L | What it usually indicates |
|---|---|---|
| 70 | 3.9 | Low end of normal |
| 90 | 5.0 | Normal fasting |
| 100 | 5.6 | Upper-normal fasting |
| 126 | 7.0 | Diabetes fasting threshold |
| 140 | 7.8 | Upper normal 2 hours after eating |
| 180 | 10.0 | High after meals |
| 200 | 11.1 | Diabetes random threshold |
| 250 | 13.9 | Very high |
| 300 | 16.7 | Very high |
General information only, based on common clinical reference points. It is not medical advice; always follow your own clinician and lab ranges.
Frequently asked questions
How do I convert mg/dL to mmol/L?
Divide the mg/dL value by 18. So 100 mg/dL is about 5.55 mmol/L. To go the other way, multiply mmol/L by 18.
Which unit does my country use?
The US, Germany and some others use mg/dL; the UK, Canada, Australia and much of the world use mmol/L. This tool converts either way.
What is the conversion factor?
18.0182. Divide mg/dL by it for mmol/L, or multiply mmol/L by it for mg/dL.
Which unit is correct?
Both are valid; countries just use different ones. Use whichever your meter or provider uses.
Is this medical advice?
No. It only converts units. Only your healthcare provider can interpret your blood sugar levels.
What is 100 mg/dL in mmol/L?
100 mg/dL is 5.6 mmol/L (100 ÷ 18). It sits at the upper end of a normal fasting reading.
What is 7 mmol/L in mg/dL?
7 mmol/L is 126 mg/dL (7 × 18). Fasting, that is the level used as the diabetes threshold.
Is 7 mmol/L a normal blood sugar?
A fasting reading of 7.0 mmol/L (126 mg/dL) is the point clinicians use to diagnose diabetes, so it is above the normal fasting range of roughly 4.0-5.6 mmol/L. After a meal, higher values are expected.
How do I convert mg/dL to mmol/L without a calculator?
Divide the mg/dL number by 18. So 90 mg/dL ÷ 18 = 5.0 mmol/L. To go the other way, multiply mmol/L by 18.