Custom invest style numbers don't add up for me.

[StayPuft]

If I set the investing style to "custom", return average to 8%, and return std-dev to 0%, does that calculate the portfolio value at retirement by just multiplying my total annual savings by 8% consistently every year until I retire?

I'm confused because when I input my figures into a more simplistic calculator with 8% return every year, compounding monthly, I get a completely different figure than what Flexible Retirement Planner pumps out.

[jimr]

Setting the investing style to custom with a std deviation of 0 should produce results similar to a calculator that does straight-line calculations without considering the volatility of returns.

The discrepancy may be due to other factors such as assumptions about taxes or inflation. Also, keep in mind that the planner displays all dollar amounts in present value (2020) dollars, not inflated value dollars, and some calculators show inflated value dollars.

[StayPuft]

Got it. I think the assumptions about inflation (or lack of) threw off the numbers in the other calculator. Thank you!