Just a general rule of thumb - the weight sticker on the individual trailer should be at least 2,000 lbs below the max tow capacity of the truck body, engine, rear axle configuration.
Just like your truck, the sticker weight on the trailer is 'off the factory floor'.
Thinks on your truck like a full size spare tire, step rails, dealer added options, etc. - are not included in your truck weight/ payload sticker.
Things on the trailer not included in the sticker weight are a spare tire, battery, propane, any dealer added options, etc. Usually adds 300-500 lbs to the trailer weight.