Jetons are from 30 mm (millimeter) till 60 mm and even bigger. Plaques you have square, rectangular and oval, also in different sizes.
Have a look at the B&G site. www.b&gchips.com
go to their productes, then jetons and there you can download a file with ALL the sizes.
The US chips are mostly 39 mm but like the Baccarat chip they are also oversized.
Hope this helps,
Kind regards,
Bob R-4479 Belgium