I was just looking at models online and I see some that are in the 54mm or 120 mm scale. I was wondering how these scales relate to 1/x scale.

Hi Sniperwolf,
the scales for 54mm is meant to be 1/35th but can be 1/32nd but varies from manufacturer to manufacturer. Even though they say they're all 1/35th the figure & kit can vary.
As for 120 mm it scales to 1/16th scale. Ive got a good link for the rest, which as per usual I cant find but will post once I find it.
Cheers,
Kenny.

Hi Again,
Here's the rest of the major sizes:
1/9th is 200mm 1/48th is 37mm,
1/72nd also known as HO/OO scale is 24mm,

I hope this helps you some, these figures are rounded up for ease. If you want to work out anyothers the easiest way to work it out is the 1 is 1 metre then divide it by 35 the scale you want to work it out in which equates to 2.857cm. The average man is say 1.90m so to work out this would be 1.90 = 1metre @ 2.857cm, 0.9 metres is 2.857 divided by 10 then time 9 = 2.5713cm total the 2.857cms + the 25713cms to total 5.4283 cms which when rounded up is 5.4cm or 54mm. This looks harder written down than it actually is. Try it .
Hope this helps,
Kenny.

Thank you

Chris