When traveling for an extensive period of time, you may need to get a haircut in a country where you do not speak the language.
I usually get a machine haircut and just saying or showing the number (length) is easy enough (you would think).
However while in the UK I usually get a 'five' and that also works in the United States and many countries in Asia, the same length in Germany is a 'twelve'.
I just came back from a haircut here in Morocco and it seems they are using 'the Spanish system' and what seems to be the same length of hair cut was a 'two'.
Is there a system behind this madness? What do these numbers actually mean?
Is there a table somewhere online that compares the different numbers and lists the countries they are used in?