<prompt> Human: Hello,whenever I see calculators for retirement plans, they always assume that you derive an income from investing your money and never touch the principal.This got me thinking - what if dont want to leave a penny to my name?That is, you just assume youll live to be 100, and the principal can be down to 0 at that point i.e., during your retirement you can use any combination of investment income from the principal and drawdown from the principal itself .Would this mean Ill need a smaller pension pot when I stop working?Does anyone know of a model calculator that shows how this would work, considering taxes and inflation?Thanks!Assistant: Im not sure if Ive ever seen a retirement calculator that assumes you cant touch the principal. The goal is generally just to not run out of money.Trying to make sure you do run out of money just before you die sounds problematic, because its very unlikely youll get the timing right. Chances are that either youll die too soon and fail to run out of money, or youll run out too soon and starve to death as a direct result.The only calculator I can recall seeing that explicitly considers death at all is this one: Human: Thanks - Im not interested in timing it right e.g., its ok if you have still 100k left at the end, but I wonder if by allowing to touch the principal youll need a smaller pot hence allowing you to retire earlier or at least at a resonable age.Do you know if thats the case?Assistant: As the first comment in this thread said, most retirement plans take into account your principle investment along with your gains when planning for your retirement. Is there somewhere you readheard that said retirement plans arent allow to withdraw principle?Human: Perhaps Ive been looking at the wrong calculators - but if youre allowed to do that, how do you make sure you dont run out of money?Can you please link to a calculator that does that? Thanks!  <response>: You cant be sure, of course, but this is why most retirement plans have you gradually shifting your money out of equities into less volatile investments, and eventually into cash, while relying heavily on actuarial charts. 