Tom is right, you can only get to about 16 years with the numbers you suggested. It is very easy to do this kind of planning on various web sites. Vanguard is great as are many others. If you just search using something like ( how long will my money last) you will find several sites that have a calculator that will let you do all this free. I can tell you also that it is not a good idea to forget about inflation. Over 25 years a lot will change and it sure won't be less expensive to live. Do your planning, most people will tell you that you will need to have some of that money invested in mutual funds to keep up with inflation. Good Luck.