Guild Wars 2

I know that 1 stack of might = 35 power, but I’m having a hard time figuring out what exactly is a healthy damage increase using might.

5 stacks? 7 stacks? In my build, I can reliably apply 9 stacks of Might (& 8 secs of Fury every 15 seconds) to allies, but is the additional 315 power a noticeable boost?

I’ve seen it mentioned that 1 stack of might = 1% damage increase, is this true?

You want as much as you can have.
The percent damage increase per might stack depends on how much power you already have.

If you have 3500 power then 1 might stack will increase damage by 1%.
If you have 1750 power then 1 might stack will increase damage by 2%