I can't throw out a fixed number if you're asking for yourself as everyone's number will vary greatly depending on their existing cost of living (debt, loans, children, location, etc etc etc...). I won't answer in my personal context either.
However, as a general rule of thumb, if you have 12 months runway base on your current cost of living AND you make enough to cover your current monthly run rate, and your projects are potentially growing or you want to free up time for working on other things or things in general, that would be a good rule of thumb.
Everyone has their own method of calculating how much they want to make before quitting a job. It depends on a few things, but they add up:
- How much debt do you have (baseline per month you want to pay)?
- How much is your cost of living?
- How much do you want for extra spending money?
- How much do you want to save?
- (Most important) How much will it cost to continue growing your company (or sustaining it 100%)?