🩸 Blood Sugar Converter (mg/dL ↔ mmol/L)
Blood glucose in mg/dL ÷ 18.0182 gives mmol/L; mmol/L × 18.0182 gives mg/dL. This converts either direction exactly. Enter your values below, results update instantly, entirely on your device.
140 mg/dL ÷ 18.0182
How the blood sugar converter (mg/dl ↔ mmol/l) works
mmol/L = mg/dL ÷ 18.0182, and mg/dL = mmol/L × 18.0182. The factor is the molar mass of glucose (180.156 g/mol) divided by 10, because mg/dL and mmol/L differ by both the molar mass and the dL→L (×10) volume unit.
Example: 140 mg/dL ÷ 18.0182 = 7.8 mmol/L. Going the other way, 7 mmol/L × 18.0182 = 126 mg/dL.
Two conventions for the same measurement: the United States, Germany and a few others report glucose in mg/dL, while the UK, Canada, Australia and most of the world use mmol/L. The 18.0182 conversion factor is exact (glucose molar mass ÷ 10), so no accuracy is lost. This tool is for converting units only. It is not medical advice and does not interpret whether a reading is high or low; discuss targets with your clinician.
Frequently asked questions
How do I convert mg/dL to mmol/L?
Divide by 18.0182. For example 100 mg/dL ÷ 18.0182 = 5.6 mmol/L. To go back, multiply mmol/L by 18.0182.
Why is the factor 18.0182?
It is the molar mass of glucose (180.156 g/mol) divided by 10. The ÷10 accounts for mg/dL using decilitres while mmol/L uses litres, and the molar mass converts milligrams to millimoles.
Which countries use which unit?
The US, Germany, Japan (partly), and a few others use mg/dL; the UK, Canada, Australia, and most of Europe use mmol/L. HbA1c uses different units again.
Is a reading of 7 mmol/L normal?
This tool only converts units and does not interpret readings, what counts as normal depends on the person, the time of day and whether you have eaten. Always discuss your numbers with a healthcare professional.
Is my reading kept private?
Yes. The conversion runs entirely in your browser; nothing you type is sent anywhere.
Is this blood sugar converter (mg/dl ↔ mmol/l) accurate and private?
Yes. It uses the standard published formula, shows its working under every result, and computes locally in your browser, your inputs are never sent to a server, and the page works offline.