[awinder]

In my opinion your number is $900,000 which is:

1500 / month * 12 months / year * 2 for taxes (this feels genetically safe as a high bar but maybe not) * 25 in order to safely pull 4% yearly forever

Trying to come up with a plan to get a business running that can safely yield 1500 / month (more for taxes) can be dicey and prone to all sorts of risk, and the time horizon is unknown. Just saying, don’t discount leveling up with learning and trying to move upwards, keeping your current lifestyle, and saving your way up.

[shoo]

I assume the meeting of the "number" stated here is an estimate of how much wealth would need to be invested in a stock portfolio to yield 1500/month net of taxes and inflation, without needing to trade time/labour for income.

Pretty reasonable, but without knowing more about OP's situation, advising someone asking how they can earn more income on the side to earn it by having $1m wealth invested in the share market may not be the most immediately actionable advice! A bit catch 22 if the current problem is "not enough surplus income".

[j_autumn]

I‘m from the EU and don’t earn a lot of money, so no wealth here which I could invest.

But I would love to be able to earn enough to live (simple, I don’t need a luxury life) while saving the rest to become financial independent at some point.