how to measure an axle shaft

Hi have a bent axle flange on a rear dana 60. Looking around for a replacement I see there are about 4 different lengths, the 29's and 31's. The difference is .25" between, how are these measured? from end of axle shaft to the flange where the studs are mounted, or is it the entire thing? I'm thinking I need either the 29.25 or 29.5.

You want to measure from the wheel mount surface of the flange to the end of the splines. :yup:

Thanks Eddie