In a sense, the USA is metric, in that the official standards refer back to the metric system. Like "an inch shall equal 2.54cm".
Nowadays, stuff in the supermarket has metric measurements alongside the English units. Which makes things easier for me, as I can never remember how many oz's to a pound (is it 12 or 16?) or what a fluid oz is, or how many to a half gallon. And I grew up in the USA. With grams or liters, it's easy.
