Hi
Depends on your fee structure.
e.g. in the city where expenses may be higher, a lower % may apply.
I don't pay more than 45% usually. Any more than that i don't make any money as the owner.
I work in Australia so it is 45% + 9% for superannuation + Workers Compensation so it comes to about 50% of the income they bring in.
A downfall of this system is that the therapist may overservice compensable patients to keep their income up.
Hope it helps!