Information provided as a general 'rule of thumb'

Will it fit my rim?

General rule of thumb for road tyres is a factor of your rim width min 1.4 and max 2.2.
For MTB tyres this increases to 1.4 min and 3 max.


So for example if the [internal] width of your wheel rim is 21mm (this is typical of a modern 650b rim), the minimum tyre size allowable would be approx (21mm x 1.4)=29.4mm or 1.16"

The maximum size for tyres on this rim would be (21mm x 3)=63mm or approx. 2.5"  (Please bear in mind frame clearance required for bigger tyres as you wouldn't want tyres rubbing on the frame).