Sizes

Hi everyone,
Question... I'm still new to the ostomy world & trying to find my way. I've just purchased a stealth belt. Being from the uk & getting it from the US it was expensive!..anyway..
The bag I use is a small, does this mean it can't hold as much as say a medium/large?
As the stealth belt seems to have capacity for a larger bag I reckon larger bag= less bathroom trips!?

I'm using a one piece bag
Cheers