In most countries, blood glucose is reported in terms of molarity, measured in mmol/L (or millimolar, abbreviated mM). In the United States, and to a lesser extent elsewhere, mass concentration, measured in mg/dL, is typically used.

To convert blood glucose readings between the two units:

Divide a mg/dL figure by 18 (or multiply by 0.055) to get mmol/L.
Multiply a mmol/L figure by 18 (or divide by 0.055) to get mg/dL.