Blood Sugar Converter

About this calculator

Blood glucose is reported in two different units depending on where you are: the United States (and a few other countries) uses mg/dL (milligrams per deciliter), while most of the rest of the world, following the International System of Units, uses mmol/L (millimoles per liter). The conversion factor comes from glucose's molar mass: divide mg/dL by 18.0182 (commonly rounded to 18) to get mmol/L, or multiply mmol/L by 18.0182 to get mg/dL.

This matters in practice whenever someone's glucose meter, lab report or diabetes management app uses one unit and they need the other — travelers with diabetes reading a foreign pharmacy label, people comparing a US lab result against European or Asian clinical guidelines, or anyone just trying to make sense of a number in an unfamiliar scale. This calculator also classifies a fasting reading against the standard ranges: under 100 mg/dL (5.6 mmol/L) is typically considered normal, 100–125 mg/dL (5.6–6.9 mmol/L) falls in the prediabetes range, and 126 mg/dL (7.0 mmol/L) or above is in the diabetes range.

Enter a glucose value, pick the direction you are converting, and get the converted number along with its fasting-range classification.