old FF lens on M43 - distance on focus ring

hi,

my experience is with old full frame lenses (M42, Canon, Nikon etc) but applies to all FF i guess,

ok so, lets take a FF lens and look at the focus ring in meters:

infinite, 12, 6, 4, 3 etc to 0,75 for example

on a FF body, you can trust these distances,

but with this lens on a M43 body + adapter, is there a raw formula like for example 8 meters on the lens = 5 meters real distance?

i think both crop factor and adapter thickness would apply,

thanks