The UK's system is very simple. Weight: stone for humans, kg for everything else, unless you're over 60 then it's lb. Or if the human is a newborn then it's

The UK's system is very simple. Weight: stone for humans, kg for everything else, unless you're over 60 then it's lb. Or if the human is a newborn then it's always lb. But younger humans measure themselves in kg. But if it's weed then it's oz. But coke is g. Length: feet and inches for the height of a human, and for the waist/leg/neck measurements. But feet? No, that's just a random number. Distances are metres, unless they're long then they're miles, and if they're at sea they're nautical miles. An aeroplane's altitude is in feet, but your altitude up a mountain is in metres. Volume is easy. Beer is in pints, so are milk and blood. But water and juice are in litres. Petrol comes in litres, but your consumption of petrol is in miles per gallon. Energy is btu if you're old fashioned and you're measuring natural gas, otherwise it's kWh, unless it's food then it's kcal. Joules are for science class. Speed is miles an hour, except at sea when it's knots. Letting each individual shop decide what measurement of weight to use will work out great.