Question 1

Do I need an account to use the calculator?

Accepted Answer

Yes. A free account lets us securely save your scenarios across sessions and devices, so your plan is always where you left it. It takes a few seconds and never requires a credit card.

Question 2

What is Coast FIRE?

Accepted Answer

Coast FIRE is the point where your invested savings are large enough that, without any new contributions, they'll grow into a full retirement nest egg by your target retirement age. After that point you only need to cover current expenses — your retirement is already on autopilot.

Question 3

How is my FI number calculated?

Accepted Answer

Your FI number is your expected annual retirement spending divided by your safe withdrawal rate (4% by default). If you expect to spend $50,000 a year, your FI number is $1,250,000. Any Social Security you enter lowers the amount your portfolio needs to cover.

Question 4

Why does it use my post-tax savings rate?

Accepted Answer

Your savings rate on take-home pay is the clearest predictor of how fast you reach financial independence. We apply your rate to your after-tax income so the contributions reflect money you can actually invest.

Question 5

Are the numbers in today's dollars?

Accepted Answer

Yes. We convert your expected return into a real (inflation-adjusted) return, so every dollar on the chart is worth a today-dollar. That keeps the picture intuitive over decades.

Question 6

Is this financial advice?

Accepted Answer

No. ProsperMap is an educational tool that models common FIRE math. It doesn't account for your full situation and isn't a substitute for personalized advice.

See exactly when your money sets you free.

Your journey to FI

What is Coast FIRE?

What's an FI number?

Frequently asked questions

Ready to map your path?