You buy soft drinks by the liter, so at least you have an idea of how big that is. After the first time you purchase an kilo of something when you really wanted a pound (2.2 pounds to the kilo) you will have a good feel for kilos. Especially if you have to eat hamburger for seemingly forever. After a while you won't need to convert because you will have been outside in various temperatures, purchased goods using the different weights and measures, and you will have adjusted, execpt to the odd things, like stone.