That's not the original definition.

FU money is being able to say fuck you to anyone (including your boss) without consequences derailing your life.

I agree with this definition. A lot of factors go into it - how much cash you have in your bank account, how easy it is for you to pick up a new job, etc. Having "FU" money doesn't mean you have to quit your job at the slightest transgression, but rather you are not desperate for the paycheck and can thus stand up for yourself. This in itself is liberating!

At the very beginning of my career I worked in the lab for 36 hours straight trying to finish a project on a tight deadline. I didn't have any "FU" money at that point obviously. If someone asked me to do that today, there would be no way! I wouldn't quit over it necessarily, but I would still be OK financially if I was fired for saying "your deadline is ridiculous!"

> FU money is literally the ability to say FU and do something anyway when someone says you can't.

So how much does it cost to travel to Alpha Centauri and back?

There are always things you can't afford, no matter how rich you are. So that's a bad definition.

Of course it isn't FU money if you insist on buying outrageously overvalued cars and real estate. There is no limit to the amount of money you need to play that game to receive increasingly marginal returns. You can be a small time billionaire and fool yourself into thinking you don't have FU money because you'd have to make sacrifices to buy that yacht you've been eyeballing

When I first heard the phrase, it was enough savings to quit your job without having another lined up? I guess people have different definitions.

> FU money is literally the ability to say FU and do something anyway when someone says you can't.

I always thought FU money was enough money that you can say FU and not do something when someone says you have to. That is, enough money to retire (get fired) on a whim. Of course, even by that definition, 750k isn't FU money unless you're single in a LCOL area (or fairly close to a predictable death, I guess).

My personal criterion for FU money is 3mm. This is fairly achievable, market willing, if you have make six figures.

If you are willing to move to another country ... 750k would be FU money in Czechia. Even for a family of four.