In a nutshell, Financial Independence is defined as the point where you are earning more money with your passive income than you need for current living expenses. Your passive income can be any income that involves little to no effort on your part to generate that money. It can include interest from savings, investment dividends, royalties, businesses you own but don't manage, websites, withdraws from retirement accounts or other investments, etc. Your current living expenses are just that, money to pay for rent or mortgage, food, utilities, travel, entertainment.
The great thing about FI is that number can be different for everyone. It's up to you, because you get to decide what your monthly expenses are and therefore what your monthly income requirement is. Maybe you want a large home for entertaining friends and family, or you 'd prefer to have a more modest home but want to travel more, it's up to you.
The great thing about FI is you get to choose what you want out of life. You also get to choose how long it will take to get there. Mr Money Mustache, Peter Adeney, retired comfortably at the age of 30. It was simple but not easy - and took hard work, but it can be done!,