In reading a bunch of different posts across the forum, I'm struck by how little $$$ by comparison I have and consider myself now "FI." Right now I have $950K investable assets (I don't include the equity I have in my house).
I determined I reached FI because a SWR of 4% on average, over a span of 35 years, as confirmed by several retirement calculators and FIREcalc, will pay for all my current and anticipated expenses pre and post receiving social security. I am counting on receiving my SS at age 67 and that's part of my calculation. I have no heirs or dependents so it's just me. There will be an inheritance I receive, but I'm not counting that in my calculations.
Yet I see some people in their 50's biting their nails with $1.3M or more in investments, not counting their house, no debt, some not even counting SS, and wondering if they can make a go of it and quit their job. Seriously?
The very definition of "FI" is that the income/dividends earned from investments along with a 4% SWR or less, per the Trinity Study, will fully cover one's expenses. I suppose if someone is planning on a more luxorious retirement, above their current lifestyle, that FI number will necessitate being higher.
If you have $1M in investments and you can easily live on $40K/year on average, and you're going to get SS benefits, then I'd say you are "FI" even if you don't think you are.