I have $1.35M in a 401K and want to draw out $100k per year. If I invest the principle at 6% and draw out $100k for 25 years, how much of the principle is left? I would like to know the equation so I can do sensitivity studies on interest rates, times and withdrawal amounts.

Thanks!

At the end of 25 years you will have ZERO left and will have had only $79,610 distributed to you in the 25th year.

You can easily do this using Excel. Subtract 100k at the beginning of year 1. Multiply the remainder by 1.06 to get the figure at the and of the first year. Repeat this process and you should get the answer billnj gave you above. This way you can play with the amount of return and the amount withdrawn to see how long things will last, etc.

Tom

Bill

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.