since they're made to haul people they're rated by passenger capacity, 3 kids to a seat.
most of our buses are 66 and 72 and i've driven a couple 75 seat thomas conventional saf-t liners.
so..that's 66/3=22 seats, two sides, 11 seats per side. the 72's are 12 seats per side.
The thomas has 13 on one side and 12 on the other. 25 seats times 3 kids per seat, 75.
Plus driver of course.
The transit we have is about 3' shorter than teh same capacity conventional but about 5' shorter wheel base (estimage when parked beside each other with rear axles lined up - same rear overhang behind the axle on both - an older bluebird transit and 2016 IC CE). (my avatar picture has the IC CE and behind it is teh BB transit)
They make 84 seat conventionals and up to 90 seat transits. Don't htink those are common though.
We've got nothing under 66 and all the new ones are 72's. Some are rostered to capacity so maybe next year's bus order will have some higher cap buses.