Kev

AS people have pointed out - postal and food scales are great but limited. If you put everything into a spread sheet, 5 pounds should be fine as what weighs over 5 pounds? Maybe some tents...

I'm lucky in that I grabbed a retired "electronics counting scale" from a place where I worked. It will weigh up to 35 pounds very accurately and it will do it in any unit you choose, lb, oz, kg, g. A scale like it is worth in the thousand dollar range or more new.

Your total pack can sit on a bathroom scale - 1/2 lb is accurate enough for the whole pack weight.

You may wish to take advantage of entering multiple gear choice combinations in your spread sheet to determine the lightest choice.

Jim