I scaled my truck in prepartion to carry a camper.
front axle = 3390
rear axle = 2470
total weight = 5860
They must be going be GVWR which is your truck's weight and it's maximum payload.
My GVWR is 7200. So if I subract the truck's weight of 5860 I net 1340 of payload which will handle my 1100 camper.