Financial Samurai breaks FI into 3 levels. Read the whole article. It’s pretty decent.
Level 1: Budget Financial Independence
If your household income is less than ~$40,000 a year, you are considered lower middle class. If you are happy with living a lower middle class lifestyle, then you would need between $800,000 – $1,600,000 in investable assets returning 2.5% – 5% a year to replicate the $40,000 in gross annual income.
Level 2: Baseline Financial Independence
The median household income in the United States is roughly $60,000. $60,000 is therefore considered a comfortable middle class income for most Americans. Based on a conservative 2.5% – 5% annual return, a household would need investments of between $1,200,000 – $2,400,000 to be considered financially independent.
Level 3: Blockbuster Financial Independence
Individual income of ~$200,000 – $250,000 and a household income of ~$300,000 was the ideal income for maximum happiness. With such income, you can live a comfortable life raising a family of up to four anywhere in the world.
Using the same 2.5% – 5% return figures, one would therefore need $5,000,000 – $10,000,000 per individual and $6,000,000 – $12,000,000 per couple in investable assets to reach Blockbuster Financial Independence. In addition, it is preferable if your home is also paid off.
I feel old and poor 
