I had a client here in Canada setting up a Woo store with a shipping plugin, which uses metric to calculate accurate shipping rates with the Canada Post API.
He entered all the shipping dimensions in inches and weight in pounds. The CM and KG units were clearly labeled. He also put the dimensions of the products, not the dimensions of the shipping boxes as asked (he bought a bunch of boxes). As a result, it calculated the wrong price.
Me: The units are too small. Your shipping box is only 2 centimeters wide?
Client: No, the product is two inches wide.
Me: You have to enter the dimensions in centimeters of the shipping box.
Client: That’s kind of r****ded, isn’t it?
Me: No, they want to know how big the shipping box itself is. It will make sense once you get the hang of it.
Client: But we don’t even use centimeters. That’s metric. Canada’s an imperial country!