In the Airstream world, the length in the literature is from the back of the rear bumper to the front of the ball hitch. Most other trailers the length mentioned is just the box, so additional length must be added for a rear bumper, if installed, and the "A" frame in front.
WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC
TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic model 30 twin beds, 50 amp service, 900 watt solar system, Centramatics, Dill TPMS, disc brakes, 16" tires & wheels