When measuring a sway bar, is it okay to use a tape to get a reading from the bar (next to the bushing) and divide by pi?

 

It's easier to use a crescent wrench like a caliper, and a tape measure to measure its opening.

 

D'oh! I should've done that in the wrecker's.

I'm going to go double check the diameter of the sway bar I pulled, just to be sure. I'm hoping that it's the 36mm bar, since it's hollow and had yellow (factory?) bushings. Came out of an 87 Trans Am.