The amount of money you need to become financially independent will depend on how much your expenses are.
When you're financially independent it usually means that you're making enough money for living expenses with money left over after paying those monthly expenses and the income usually comes from things such as assets or any other ways that you make passive income.
Being financially independent in my understanding is where you don't have to depend on employment to earn your living plus having money left over.
If you spend $20,000.00 per year you need to have $500,000.00 in your savings or checking account to be financially independent.