1. Save and invest approximately 25 times your annual expenses. For example, if your yearly expenses are $30,000, you need to have $30,000 25 = $750,000 in your investment account before deciding to retire. This number is called the financial independence number (FI). FI depends upon your targeted yearly expenses. 2. After you achieve your FI, make small 4% withdrawals, known as a safe withdrawal rate from your investment, such that $750,000 4% = $30000. 3. This FIRE method is feasible because the US stock market index fund gives ~10% return on average, US inflation is ~3%, and the dividend yield is ~1%. Thus the real return on investment is 10-3+1=~8%. If you don't withdraw 8% or more, you will always have your nest egg, and you can indefinitely live off your investment. Q1. Say you are 25, and you plan to work the following 20 years to retire. What lump sum amount do you need to save and invest today to achieve your FI? Assume an 8% real rate of return per year. Show the math and interpret your answer. Q2. But, saving and investing such a large lump sum is not feasible when you are just starting your journey. Hence you decide to make a monthly contribution to your investment account; what would be such a monthly contribution? Use the following calculator here. Say your starting amount is 0, years to save is 20, rate of return is 8%, frequency is per month, and interest compounds annually. Try and play with different numbers in the "additional contributions" placeholder. Q3. So, when you start your new job at the age of 25, what should be your expected annual salary to achieve your investment goal along with yearly expenses of $30000?