Amaranthine t1_iuh88um wrote on October 31, 2022 at 9:23 AM

Reply to comment by 52MeowCat in TIL that in ancient times, the carob seed was used to measure the worth of gems and gold since the seeds have a general uniform weight. This is where the word "karat" comes from. by kkoolook

I assume barley/poppyseeds are also pretty consistent, which is why UK (and US) sizes are based off that :)

So for anyone wondering what one shoe size is and why it doesn't quite map with centimeters... it's because 1 US size is a barleycorn, which = 1/3 of an inch; close enough that sizes will more or less map to 1cm (2.54cm per inch), but not qute.