The majority of typewriter typefaces came in one of a few sizes either pica (10 characters per inch) or elite (11 or 12 CPI). Usually you can tell by the number of characters on rule at the back of the paper table. A scale that goes up to 85 is usually indicative of Pica machine (85*10 CPI = 8.5", which is the standard paper width in the US) and a scale that goes into the the 90s up to 102 indicates elite. There were definitely other sizes for custom typing, but they're rarer. You might see things like 6 CPI which was used for children or people with vision problems and machines that go up to 18 CPI. I've heard rumors of 20 CPI, but never seen one.

1958 Olympia SM3 Final Type Test -Part6: COMPLETE Olympia SM3 service and set up guide. by [[The HotRod Typewriter Co.]]

Gerren prefers cotton ribbons in pica machines because the larger typeface can better handle the ink.

Typewriter Typefaces: Pica vs Elite, an explainer https://www.youtube.com/watch?v=qwCD69jUPps

Pica machines (12 characters per inch) will usually have a scale up to about 80-84.

Elite machines (10 characters per inch) will have a scale up to 100.

On Olympia machines, script only comes in Elite sizes (scale to 100 on platen).