Retirement Calculator

by Melinda Green


NOTE: While you can still download the stand-alone Java desktop app here, it will not be maintained. You should instead use the Android version if possible.

Wondering how much money you'll need to retire? How about how long you can live on what you have now? So many questions! There are four main variables that affect your retirement income from your investments:

Basic Assumptions

Many people plan to try to live only from the interest from their investment as if they were going to live forever. Clearly one can increase their standard of living by also dipping into their principal, but for how long? With this little applet you can easily explore "what if" scenarios involving these variables under the assumption that you will be broke at the end of the time you expect to live. Of course you might live longer than that and it would be terrible to be broke when you are very old, but it would be worse to be dead! Of course if you expect to live for 20 years after retirement, planning for, say, 40 years should be plenty. Many people think that if they never touch their principal, at least they will leave a nice sum for their children, but that money would likely mean more to you in your retirement than it would be to your kids.


The selected row is the current variable being solving for. By default the "Expenses" variable is selected. This means that you can see how much you can draw each month depending on the values you enter for the other three. For example, if you expect to live at most 25 years after retirement and expect to earn 5%, you can set those values and then adjust the "Wealth" slider to see how much money you will be able to live on each month depending on your net wealth at retirement. You can also see the effects of different interest rates and retirement time on your expenses. Conversely, you can select to solve for "Wealth" in order to see how much you'll need in order to retire with a particular desired monthly disbursement.

You can even solve for "Interest" to see what sort of interest rate you'll require, and you can solve for "Death In" to see how many years you can live given the other parameters. Play with the applet for a while and you should get the idea of how to answer many other interesting "what if" scenarios.


There is no particular error checking of inputs though it should be obvious when a variable goes out of scope when a slider jumps to a new location and doesn't move.


Of course no warrantees are made as to the utility or accuracy of this tool. It's really just a tool for getting a rough idea of possible retirement scenarios, and is not a replacement for expert advice from retirement professionals.

Source Code

The Applet's Jar file is executable as a stand-alone application and also contains the Java source code free for general use.

Return to