FIRE RETIREMENT CALCULATOR
FireCalc
FIRE Retirement Calculator
One number would be a lie. This gives you the range.
FireCalc takes your savings, your contributions and the age you want to stop, then runs a thousand different market futures over the plan. What comes back is a spread of outcomes and how often the money lasted — not a date, and not advice.
Free to try, including one simulation.
$1.99/mo · $9.99/yr · $24.99 lifetime.
WHAT ONE RUN RETURNS
A thousand futures, then the spread.
Press Run Simulation and FireCalc draws a thousand independent return paths across the whole plan. Every path is a different market history, and they fan out the further from today you look.
- Success rate
- The share of the 1,000 paths where the money lasted to your life expectancy.
- Median ending balance
- The middle outcome. Half the paths finished above it.
- 10th percentile
- A bad run. One path in ten finished at or below this — often at zero.
- 90th percentile
- A good run. One path in ten finished at or above this.
- Worst case
- The age at which money ran dry on the worst path the simulation drew.
Above is a diagram of the shape, not of your plan. The real figures come from your own numbers when you run it, and they change every time an assumption does.
How the projection is built
All of this is written out inside the app too, on a screen called About the math. A simulator that will not show its working is just a number generator.
- 01
Everything is in real terms
Return and inflation are combined into one real rate before anything else happens, so every figure on screen is in today's money. There is no separate inflation slider to get wrong.
- 02
The simple projection first
Your FIRE number is your target annual income divided by your safe withdrawal rate, 4% by default. The free projection grows the portfolio with your contributions, then withdraws the target income each year of retirement.
- 03
Then a thousand of them
Rather than one fixed return, the simulation samples 1,000 return paths from a normal distribution parameterised by long-run real return and volatility, blended by an implied equity weight. Box-Muller sampling, run on the phone.
- 04
And the years that actually hurt
The sequence-of-returns view replays your plan against summarised first-decade real returns after 1929, 1966, 1973, 2000 and 2008. Two identical portfolios can end very differently depending on when the bad decade lands.
Three ways to stop, three ways to draw
Each scenario picks one from each column, so the same savings can be tested as an early coast, a part-time bridge or a straight retirement.
FIRE MODE
- Traditional Contribute until you retire, then live off the portfolio.
- Coast FIRE Stop contributing now and let what you already have drift to retirement age.
- Barista FIRE Part-time income after FIRE reduces how much you have to withdraw.
WITHDRAWAL STRATEGY
- Fixed Real (SWR) Withdraw a fixed amount each year, adjusted for inflation. The classic 4% rule.
- Guyton-Klinger Raise or cut spending when the withdrawal rate drifts outside its guardrails.
- Variable % (VPW) Spend a rising percentage of the current balance as you age.
ACCOUNTS
Accounts can be labelled SIPP, ISA, 401(k), IRA or Super, and each carries a tax-treatment note — tax-free or tax-deferred. That is a label and a note. FireCalc is not a tax engine and applies no country's rules to your withdrawals.
It also keeps progress check-ins, so you can record where the portfolio actually got to and compare that against the plan, plus a CSV export of the year-by-year projection.
Six screens from the app
Drag the row, or focus it and use the arrow keys.
Scroll sideways, or use the arrow keys
What FireCalc is not
FireCalc is a calculator, not financial advice.
That line is the app's own, shown on first launch and repeated under every result. The rest follows from it.
- Not a forecast. Hypothetical simulation using long-run historical return statistics. Past performance is not a reliable indicator of future results.
- Not a guaranteed rate. You supply the assumptions. Change the expected return and every figure moves, which is rather the point of running it a thousand times.
- Not a tax or benefits calculator. No tax computation, no state pension modelling, no country-specific rules.
- Not translated. English only, whatever language your phone is set to.
PRICING
- $1.99monthly
- $9.99yearly
- $24.99lifetime
Free gives you one saved scenario, the simple projection, three progress check-ins, and a single Monte Carlo run so you can see the output before you decide anything. Anyone who bought the earlier one-time unlock keeps full access permanently.
- Unlimited scenarios and simulations
- Sequence-of-returns comparison
- Guyton-Klinger and VPW strategies
- Unlimited progress check-ins
- CSV export and cloud backup
- No ads
Questions
Does FireCalc tell me when I can retire?
No. It models. It shows how a plan behaves across a thousand possible return paths and how it would have fared through some bad decades. That is a range of outcomes, not a date, and it is not financial advice.
What does the success rate actually mean?
It is the share of the 1,000 simulated paths in which the portfolio still had money at your life expectancy. A 74% result means about one run in four ran dry, which is information about risk rather than a probability of your future.
Does it handle tax on a SIPP, ISA, 401(k) or IRA?
Not as a tax engine. You can label accounts by type and each carries a tax-treatment note, tax-free or tax-deferred, but FireCalc does not compute a tax bill or apply any country's rules.
Do I need a connection?
No. Scenarios and simulations run on the phone. Cloud backup is optional, and there is a CSV export of the year-by-year projection.
What is free?
One saved scenario, the simple projection, three progress check-ins, and a single Monte Carlo run so you can see what the simulation returns before you decide.
I bought FireCalc before the subscription. What happens to me?
Nothing. The one-time unlock is grandfathered permanently — those buyers keep full access and are never asked to subscribe.
Run it once on your own numbers
Build a scenario, press Run Simulation, and read what a thousand different market histories do to it.
FireCalc is a calculator, not financial advice. Estimates only.