That's correct Terry.
If you weight it empty, that's the weight of the frame and bed etc.
Anything you add will add that is behing the front axel will add to the rear axel. Maybe not 1:1 ratio, but for discussion assume that.
Cargo, hitch weight, cargo, passengers, fuel, TT tongue weight, etc
You can look on the side of the tires for weight rating. Multiply by number of tires on axel.
My TT CVWR is 3500lbs. My 13" D rated tires are 1725lbs
2016 Toyota Tundra SR5, 5.7 V8