On the day we set off for Scotland we had our van weighed at the Refuse Recycling Centre, free if he wrote it down on a slip of paper, or £35 for it to be printed out - we went for the paper slip.
We were fully loaded with a full tank of diesel, full water, 2 dogs with their gear as we were dropping off to kennels on our way. Both Mark and I had packed clothes for all eventualities in the weather (brought a lot of it back unworn!) and I'd also packed plenty of food, plus bottles of water.
We're registered at 3500kg and weighed in at 3140kg - 360kg to spare and pretty sure we'll have difficulty in going over that for any trip.
You obviously don't carry ebikes, fishing dinghies and related fishing equipment, and climbing gear!!!
We know we are just (under) borderline carrying such things if we have only half a tank of fuel, third of a tank of fresh water (no waste water) and a depleting gas allowance!
Of course we could go on an even more strict diet and go tee-total (so no associated mixers)!!!
That would make us lighter still!