FIRE Calculator — Financial Independence Planner
Calculate when you can achieve financial independence based on your income, expenses, and savings rate. Uses Monte Carlo simulation with dynamic safe withdrawal rates to find your FIRE age across thousands of market scenarios.
Estimated FIRE Age (Median)
43
FIRE Age Range (P25–P75)
41 – 45
Overall FIRE Probability
100.0%
Current Savings Rate
50.0%
Annual Savings
60,000
Retirement Spending at FIRE
60,000
Safe Withdrawal Rate (SWR)
4.2%
Required FIRE Portfolio
1,414,313
Fan chart showing accumulated portfolio (MC) vs required FIRE portfolio crossover
Cumulative probability of reaching FIRE by age
How different spending levels affect your FIRE age
What this FIRE calculator does
It projects your path to financial independence with Monte Carlo simulation rather than a single compound-growth line. Income, expenses, and their growth rates generate annual savings; each simulated path grows your portfolio through resampled historical returns and records the age when it crosses the required FIRE number.
A dynamic FIRE number, not a fixed 25x
The required portfolio is computed from a safe withdrawal rate matched to your risk tolerance and the retirement length remaining at each candidate age — not a fixed 25x multiple. Retiring at 40 needs a larger multiple than at 60, and the calculator prices that in automatically.
Reading the results
You get a median FIRE age with a P25–P75 range, the probability of reaching FIRE at all within your working horizon, and a sensitivity chart showing how spending changes move the date. Savings rate is the dominant lever: cutting spending both increases savings and lowers the target simultaneously.
Frequently asked questions
- How much do I need to retire early?
- Roughly 25-30x your annual retirement spending, depending on horizon and risk tolerance. The calculator computes your personal multiple from a dynamic safe withdrawal rate rather than assuming 4%.
- Why does my FIRE age come as a range?
- Market returns during accumulation vary enormously. The P25–P75 range shows how much a lucky or unlucky decade can move your date — often by 3-6 years at typical savings rates.
- Does it account for spending changes after retirement?
- You can set retirement spending independently of current spending, or let it track your current expenses grown to the FIRE date.