system
Given the following post, respond as if you're commenting on Reddit:
human
How do you actually measure the mass of a mountain?

How do you know the volume? Density? What area is considered to be part of the mountain?

I've seen the mass of Mt. Everest mentioned as a comparison to other things in several videos, articles and such and I always wondered how this number comes about.
gpt
first you make some assumptions on where the mountain starts and ends and get a rough volume, then you multiply by a average density of rock, dirt, soil, water and void spaces, roughly 2,500lbs/cubic yard.

While it won't be perfect it should be within 20% or so...