There is a lot of literature on the subject and I’m no expert but basically the error is that financial advisors assume you will want a certain percentage (believe it’s 70%?) of your pre-retirement INCOME. They don’t really base it off your actual expenses.

The distinction is important because your expenses can be a lot less than your income (indeed they should be). And research shows expenses over all tend to go down the longer you’re retired.

Figure out what your expenses will be first. This can be as bare bones or generous as you’d like, depending on what you plan to spend your time doing in retirement. Add a buffer for unforeseen expenses and divide that annual number by .04-.05, depending on how conservative you want to be. That’s what you “need” to retire.

If you want to factor in social security, which you should (anyone who thinks taxpayers and voters are going to allow the single most popular entitlement in America go bankrupt are mistaken, and last I read even if the SS trust runs out of money the system will fund itself at least 75% perpetually based on ongoing payroll taxes), subtract whatever you project to receive from SS from your annual number, then add the buffer and divide by .04-.05.