Use metric units of measurement, except in specific cases where imperial units are still used as standard.
feet and inches
pints (for beer, cider and milk)
acres (for land registration)
Write out measurements at first mention, then abbreviate. If it’s only mentioned once, don’t abbreviate.
12 kilometres per hour (kph)
Abbreviations shouldn’t have full stops and are always singular. Use a space between the number and the abbreviation, except with one-letter abbreviations.
Write out “miles” and “metres” in full.