Dexcom Readings

Hi - I have connected my Dexcom app to home assistant. It gets the values but its in American format. I need to display UK format.

Its an easy calculation to make - you take the USA value and devide it by 18 to get the UK format. Can you please tell me how to do this so that the correct format will show in Lovelace?

In configuration, set the units to mmol/L