Blood Sugar Converter (mg/dL ⇄ mmol/L)
Convert a blood glucose reading between mg/dL and mmol/L instantly, in either direction. The two units are different ways of reporting exactly the same measurement, so nothing about your reading changes — only the number format does.
Convert
Enter a value on either side
Type into whichever field matches your meter or lab report; the other side updates as you type. mg/dL is shown as a whole number, mmol/L with one decimal place.
Conversion result
Enter a blood sugar value above to see it in both units.
Why two units
mg/dL and mmol/L measure the same thing
mg/dL (milligrams per deciliter) reports the weight of glucose in a volume of blood and is the standard in the United States and a few other countries. mmol/L (millimoles per liter) counts glucose molecules per liter and is the standard in the UK, most of Europe, Canada, Australia, and China. Meters, lab reports, and research papers mix the two constantly, which is why the same fasting reading can appear as 100 in one report and 5.6 in another.
mmol/L = mg/dL ÷ 18.018 · mg/dL = mmol/L × 18.018
The 18.018 factor comes from the molar mass of glucose (about 180.18 g/mol) combined with the deciliter-to-liter volume difference between the two units.
Common blood sugar values in both units
| mg/dL | mmol/L |
|---|---|
| 70 | 3.9 |
| 100 | 5.6 |
| 126 | 7.0 |
| 140 | 7.8 |
| 180 | 10.0 |
| 200 | 11.1 |
Some of these values appear in clinical guidelines, but the table is only here to help you read a number written in an unfamiliar unit — it does not interpret or grade your own reading.
FAQ
Blood sugar unit questions
Why are there two different blood sugar units?
Laboratories standardized differently by region. The United States and a few other countries report glucose by weight per volume (mg/dL), while most of Europe, the UK, Canada, Australia, and China report it as a molar concentration (mmol/L). Both units describe exactly the same glucose level in your blood.
How do I convert blood sugar from mg/dL to mmol/L?
Divide the mg/dL value by 18.018 to get mmol/L, and multiply a mmol/L value by 18.018 to go back to mg/dL. The factor comes from the molar mass of glucose (about 180.18 g/mol): 1 mmol of glucose per liter weighs about 18.018 mg per deciliter.
What is a normal blood sugar level in mg/dL and mmol/L?
Commonly cited reference points for adults without diabetes are a fasting glucose of roughly 70 to 100 mg/dL (3.9 to 5.6 mmol/L) and below 140 mg/dL (7.8 mmol/L) about two hours after a meal. These numbers are shown for orientation only: this page does not interpret your reading, and only a clinician can evaluate your individual values.