Financial Independence Retire Early. Very simple and easy to use calculator to chart if you are on track to retirement. The younger you are, the larger the effect of small changes. Start by inputting your current information: Current Age, Expected Retirement Age, Salary, Savings, and how much you put into savings per year. From there, make adjustments to the sliders so that your retirement does not run out too early. Or adjust your conditions so that you do retire early.