Pilot, this is one of those things I assumed I knew...until you asked.
I looked at Oregon's site FAQ Oregonョ Frequently Asked Questions and you almost have it: tip of bar to fartherest cutter....rounded to the nearest inch. The rounded part threw me.
I would have answered from tip to adjuster holes in bar at mount end...and been wrong.
Turnkey, I have a Husky 51, great saw, love it, but usually only gets use on hunting/camping trips, a bit light for serious firewood cutting.
RavensRoost
How is bar length measured? The total length or the portion beyond the powerhead, i.e., the length that you can actually use?