Skid steer tire sizes are measured like this:
TIRE DIAMETER x TIRE WIDTH – RIM DIAMETER
Skid steer tires are not measured the same as a typical, everyday tire you’ll find on a car or truck. Skid steer tires, both inflated and solid, come in sizes such as 31×10-20, meaning the tire diameter is 31”, the tire width is 10”, and the rim diameter is 20”.
Ameritrax sells solid skid steer tires in three sizes: 31×12-20 (replaces 10-16.5), 33×12-20 (replaces 12-16.5) and 36×14-20 (replaces 14-17.5)
Ameritrax solid skid steer tires are available in both traction and smooth tread.