Common Romanian expression (and mistake) to refer to a liter of milk. Everybody says it, but when they say so, they always mean one liter (a bottle, which has a liter). Practically, a kilogram of milk is less then a liter, due to the fact that milk is about 3.5% heavier than the water, due to casein and other fats dissolved in it. So now you know, if a Romanian asks you for a kilogram of milk, don't give him only 965 milliliters, if you don't want the bottle broken on your head... :P
Interesting that I used to say ”un litru de lapte” since I was very young, without having any idea about the difference, due to the fact that it is much easy to pronounce. Laziness... And it stayed like that. (these little stories are meant to serve you as memos, hehe).