How do you find which tire sizes fits on your rim?

prices vary . .even within the same size.
225/40r18 can be $300 each or $146 . . and everywhere in between.
you get to pick when you see the list.
All tire stores want to start by selling what they stock.

What do you consider as a tire shop? Iā€™m in Quebec Canada so all I know nearby is Costco and Canadian Tire.

Hopefully youā€™ll also consider the tire size relative to the rim width as well as just the rim diameter. Thereā€™s been a popular practice among some young kids in my area to put tires on that are clearly much too narrow for the rims. They think it looks cool, but it can seriously compromise the integrity of the beadā€™s seat. That can cause a sudden and total flat when hitting a pothole, and that is a compromise in safety.

Iā€™ve attached photos to illustrate.

A place that sells tires. Come on , you are making this way too complicatedā€¦

Man I donā€™t know, Costco and Can Tire are pretty crappy places overall car related work.

popular practice among some young kids

Ha ha, thatā€™s just idiot ricers. So dumb.