Yes four inch heels does have a ring to it. Here in Britain we use both measurements regularly. Our speed limit signs are in mph, but we guy our food in grams and kilos. We measure our height in feet and inches and talk about our weight in pounds and stone. Screws and bolts are metric, as are most tools. We buy petrol in litres but talk of miles per gallon. It can be weird.
a mile walk in 10cm heels - to continue our mixed use if measurements - is impressive. The weather was vile out today so I went nowhere but wore my 10cm heels indoors all day. I should have worn my 12cm but I was lazy and the 10cm are so easy to walk in. It felt really odd, deflating, to take them off at the end of the day.