If I'm understanding your question, you want to know what size rod to order? For 32" windows, you'd order the 4ft length. You'll have to cut them down to size a bit to about 40 or 41".

I was actually asking about the diameter of the rod. 1 3/8" or 2".

I was thinking that to have the rods be wide enough for the curtains to stack back they would have to have an extra foot on either side at least, 32+24=56", so I'd order the 6 ft rods and trim them.

I just ordered 1-3/8" for my bedroom with 9 ft ceilings. My living areas have 2"+ rods with 9 ft and vaulted ceilings, but the windows are all pretty large double/triple ones. I hate thin skimpy rods, so I would rather end up with a rod that is a bit thicker. The 1-3/8" should work well for your smaller windows.

Do you have a Calico Corners near you? They have a lot of the Kirsch hardware on display and if you are like me, and would like to see/touch/feel the items before you buy.

I have 1 1/8 and stuck with that when getting my new rod, as it is black and already makes a bit of a statement. If I was going stainless, I'd get a bigger/thicker rod. If that makes any sense at all!