I completely understand time value of money, and I'm going to propose an alternative way of thinking about retirement: You may want to assume no rate of return

I completely understand time value of money, and I'm going to propose an alternative way of thinking about retirement: You may want to assume no rate of return above the rate of inflation over the long term in your retirement calculation. Why? Because, if you assume you have a rate of return, you must assume you are taking risk in order to get returns above the risk-free rate. Rather than assuming you will earn interest in the market, people may want to consider the strategy of saving like they won't earn interest and scaling back as they get older. The OP suggests that the past 139 years may not look like the future 139 years. I'd say they almost definitely won't. The current generation entering retirement has very big problems ahead, and the younger 20-35 year old generation will have even larger problems with retirement. If you follow my strategy, retirement planning is easy: 1) Assume no inflation in either investments, salary, future needs (this makes sense since they match) 2) Figure out how much money you want to live on in retirement using today's dollars. 3) Divide the number by an assumed interest rate. I'm using 5% for my retirement. (that number is higher than you would get today in income and lower than what has occurred over a long period of time.) In order to have $100,000 a year salary in retirement, you would need to have $2M in the bank in today's dollars. +++This isn't a perfect calculation, but seems far more realistic than assuming you will earn a return above inflation. (An alternative would be to assume you earn a leveraged return above inflation. Its more risky, but could be argued.)