The longer the period which is being estimated, the more accurate these assumptions can be expected to turn out. If your estimates produce unrealistic results, go back and review your assumptions. Step C - Make a Plan requires a lot of number crunching. It is possible to work out rough estimates with pencil and paper. If you are so inclined, you might make up an Excel spreadsheet.
Most people find it is easier to use one of the software packages mentioned above.
But beware, the planning software on these sites will often produce widely different results. Fitting together the probable outcomes based on all this input is an area to which you will want to dedicate some considerable attention. Click here to perform the calculation online, or here to download a printable form in PDF format. That is your action plan. Reallocate your investments and purchase new investments based on the asset allocation you have determined.