Literally never know what my trail weight is because the pack gets final packing at the trailhead. Food, water and those last "extras" go in and sometimes, things come out because the food is too bulky.

Water can be a significant variable because sometimes only at the trailhead (or ranger station) do I get a sense of how much to carry. One of several things I miss about hiking the PNW is the availability of water on the go.

Sad!