How to know "your number" for a machine haircut in a foreign country?

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?

• I would assume pointing with two finger would be universal? Better than the numbers, which are also confusing for clothes, shoes, etc. Mar 26, 2013 at 22:27
• I think in Germany they are using mm, in morocco they are using cm...in the US they are using the fifth trimmer guard which is around this length (2 cm). I am just guessing.. most likely I am wrong. Mar 26, 2013 at 22:41
• I'm not sure what a "machine cut" is, but one strategy might be to show the barber a picture of you with your hair at the desired length. Mar 28, 2013 at 17:49
• I was pleasantly surprised numbers in Croatia were (at least approximately) the same as back home in the USA--and subsequently quite confused that the numbers in Singapore have the opposite relationship with hair length (#4 is shorter than #3, for instance)! Dec 31, 2015 at 4:11
• Hmmm, sixty-some years and i never heard of a number system. I described in detail how long I wanted it, reinforced with pointing where it should end, and the guy did what he wanted anyway. .... Oh, I'm a little slow; you're talking about thickness or depth, not length. Dec 31, 2015 at 6:59

In Spanish Wikipedia, Hair clipper article has an explanation about that. I'm Spanish and I have always seen this system:

(roughly translated)

Each number means 3 mm or 1/8 inches (= 3,175 mm).

Number 1: 3 mm - 1/8".
Number 2: 6 mm - 2/8" (1/4").
Number 3: 9 mm - 3/8".
Number 4: 12 mm - 4/8" (1/2").
Number 5: 15 mm - 5/8".
Number 6: 18 mm - 6/8" (3/4").
Number 7: 21 mm - 7/8".

Now I'm living in Italy and I bought here an electric clipper (Philips) that uses this same system.

If you went to Morocco and they used this system and nº2 is equivalent to a UK&US 5, it's pretty probable that you measure it in millimeters (maybe you already know it, anyway it is only my guess), but I have no idea what German number (12) can mean.

Maybe people from these countries can tell us how many millimeters it is "a number".

EDIT: Unfortunately I can't speak German but I have googled for understanding UK & US notation and I have found this web. It seems to be American and, although it depends of the clipper brand, as an example this is the representation:

00000 - 1/125"
0000 - 1/100"
000 - 1/50"
0A - 3/64"
1 - 3/32"
1A - 1/8"
1.5 - 5/32"
2 - 1/4"
3.5 - 3/8"
3.75 - 1/2"

So my supposition above was wrong.

This other page, maybe American too, or perhaps international, shows a system like the Spanish one.

What I usually do is use pictures instead. The next time you get a good haircut, ask a friend to take a few pictures of your head or take some selfies. Then every time you go to a barber shop in any country show them these pictures and they will know what to do. A lot more reliable than trying to guess the local number system :)

This is a very old question but the truth is there is no real answer

All counties have different systems, having said that all (usually) follow a simple rule - which do they use day to day? imperial or metric? If its metric its 3mm per grade and 1/8 if imperial. This is the only answer to this kind of travel problem without listing every single country

Overall the best way of dealing with with this problem is to show them a photo

If you like this please also like @machlas answer as its absolutely correct (as far as it can be) but offers no solution to the problem - so while it doesn't answer the question you should take a photo if you are unsure and think you will stay long enough to need a haircut

• 3mm and 1/8" are close enough to make no difference. That is not what this question is about. Apr 11, 2019 at 1:37

In the US we use the 8th inch system:

1 = 1/8 inch 2 = 2/8 inch 3 = 3/8 inch 4 = 4/8 inch 5 = 5/8 inch 6 = 6/8 inch 7 = 7/8 inch 8 = 1 inch

However, I live in Rome, Italy and when I go to a barber sometimes they use this system and sometimes they use another system, which may just be millimeters. I had a really bad surprise this way last time I went and lost all of my hair. In both the US and Rome most barbers I have seen use Wahl brand clippers.