What fork size is 32mm (inside diameter on the frame) considered?
If you have a 32mm approximate head tube inside diameter, this is an 1 1/8" frame, assuming it is a standard headset design. 

An 1 1/4" head tube would have approximately a 35mm inside diameter. 



Here is a link to a PDF from Cane Creek detailing most other styles of headsets fitment for non-traditional options. 

These have become very common also.