Very very cool. Only thing I wish is that the retirement spending was also indexed to inflation. Every other field is in today's dollars. Unfortunately, this make this calculator overly optimistic, particularly over long time frames. Nice job though!

Thanks for the calculator but there is something weird with it. (friendly feedback)
Somehow if I reduce the safe withdrawal (meaning I will withdraw less) the FIRE number increases.
It should be the opposite. If I expect to withdraw more, FIRE number should increase, if I expect to withdraw less FIRE number would decrease since my expenses are less.
Just saying.
In an scenario of having 200k by age 35 that should be already a coastfire with retirement at 65 and annual expenses of 60k
However the calculator is telling me I will never reach coast fire. :S

Consider someone who wants to live on $40K in retirement and is weighing a 3% vs 4% SWR. X = the FI number for a 3% SWR, and Y = the FI number for a 4% SWR

0.03*X = 40000
0.04*Y = 40000
X = 1.33 Million
Y = 1 Million

All else being equal, the pot of money has to be larger to provide the same amount of living expenses at a smaller SWR.

The SWR has only one function, to determine what your FI number is. If you plan to spend 50k a year in retirement and SWR is 4%... Then your FI number is 1,250,000. If SWR is 3% it is 1,666,667. Lower the SWR, the more money you need. Coast FI is a whole different concept but is tied in to what your FI number is.

I recently found your site and this calculator. It is helpful, thank you. I am wondering about the current invested assets category. I have a home that is paid off and used as a rental. I believe that falls under the invested asset category, but was wondering if you would consider it as such? Thanks.

The term "Safe Withdrawal Rate" is being misused in the calculator. A SWR is determined by investment returns (which in turn depends on asset mix, amount invested, etc), inflation, longevity--it can't be selected as an input in this sort of calculation. The item should be labeled "Withdrawal Rate," which is the rate of withdrawal that you select when spending your invested funds.

This tool is great. I've been obsessed with it for several days now. I do have some questions:

1. What does Monthly Contribution refer to? Is that the amount of dollars between NOW and CoastFIRE or is it continual contribution even after reaching CF? I guess it wouldn't be Coast FIRE if you had to keep contributing, so I'm asking for a confirmation.

2. I don't see it mentioned, but what about Social Security benefits? For example, I think I need $65k/yr in retirement. Should my SS be included in this number or would it be extra on top of the $65k?

THANK YOU!

Monthly contribution is how much you're able to contribute per month and once you hit Coast FI... You would stop making any sort of monthly contribution and use that money to cover your living expenses instead until your retire. If you kept contributing monthly past coast FI... That's denoted by the dashed line. Obviously, the dashed line will intersect with the orange FI line sooner than if you coast FI and stop retirement contributions when you reach coast FI.

For SS, that's always tricky. Most people who have enough assets will wait until 70 where you get the best value for SS. Yes, in theory you could reduce your annual expense in retirement number once you hit 70 but you can't really do it here.

Thanks Adam! You're an angel. Cheesy but true.

This calculator doesn't include reinvested dividends which affects the calculation hugely.

That's always implied in growth rate of investments. When they say the market return is 8% , that's a mix of stock appreciation and dividends. There's different data showing the breakdown of the two pieces but it's usually around 3% dividends and 5% appreciation. If dividends are not reinvested your return would be much lower. You would have to assume that any dividends received just sit there in cash. Assuming your retirement savings are building in tax sheltered accounts, there's zero reason to not reinvest dividends.

Hello.
Thanks for this great tool, can you also include the "Net worth with continued contributions" to appear in the box when you interact with the chart?
Cheers