[FabHK]

Wikipedia:

"As of 2017, seven countries formally do not use the metric system as their main standard of measurement: the United States, Myanmar, Liberia,[3] Palau, Marshall Islands, the Federated States of Micronesia, and Samoa.[4] However, both Myanmar and Liberia are reportedly essentially metric, even without official legislation."

https://en.wikipedia.org/wiki/Metrication

[JacobJans]

Formal use is different that widespread consistent use, excluding the other system.

My observation, at least where I live, is that both systems are used in practice. Especially at grocery stores, where the aim seems to be intentional confusion. For example you buy oranges listed for 2.34 a pound, but at the register you are charged 5.74 a kilo. Where you charged the correct rate? Maybe? Maybe not?

[merb]

well in germany you still say "ein pfund" (one pound) or "halbes pfund" (half pound) if you buy sausages/meat. but you mean 500g and not the real value of one pound. it's just that this is used because we got used to it. we also have a wierd system for the clock where we say "viertel vor" (a quarter to) or "viertel nach" (a quarter past). which is pretty common to say the time in quarters instead of values.