Using Inch or cm/mm from metric system for americans and canadians?

Question

We're developing an international product that displays a ruler to the user. Now in Germany and many other countries its of course common to use the metric system: cm or mm.

I'm aware that americans and canadians (and maybe others too) do still use inches, feet and yards.

So the question is: will todays americans (and other inch-country-citizens) understand the metric system and take it for granted - or do they still love their inches so much that they'd rather die than use a product with incorrect measurements? ( sorry for being blunt ;) )

Answer 1

One thing is certain : which units are used must be obvious in the interface any place where you show a dimension (aka avoid the excel set column / row size dialog with no unit).

I also guess that alas you'll have to handle both systems. Some americans know about the metric system but not all of them. And even the ones who understand it don't necessary love it.

What I would do : default to metric system but provide some options to change it ...

Answer 2

The only places yet to adopt the metric system are USA, Burma and Liberia. I think that in these places, people would love to have the English measurements as their default. I don't think USA citizens are comfortable enough with the metric system to actually use it (with exception to engineers and scientists).