Drifting off topic here, but I was in the US earlier this summer, and for fun tried to figure out what the percentage of salt was in a can of soda. It contains X fl.oz. It has Y mg. of salt. Thats Z % of the recommended daily allowance. I gave up.
IMHO the USA is a bit challenging on units in general.
Did you know that one US mile is 5280 feet and one US gallon is 148.94684081 US liquid ounces ?
Doesn't make sense where I come from :-)
Online Conversion - Volume Conversion