In the UK the metric system is used in business, construction, science etc. Really anything serious. Imperial measures seem to persist informally for things that are difficult to visualise, like body weight or speed. Or things that are customary like a pint. I will ask for a pint because that is how much beer I want to drink. Not because I actually care what unit it is in. And young people haven't got a clue how to add up pounds and ounces or inches and feet.