What is a FIRE Planner?
Most FIRE calculators give you a single number. Useful for five minutes, then you close the tab. A planner is different — it models your entire financial picture over time: assets growing at individual rates, debts being paid down, income streams starting and stopping, expenses inflating, and one-time events like an inheritance or a home purchase.
This planner runs a month-by-month simulation across 30-50+ years. Every month, it compounds each asset at its own rate, applies contributions, accrues debt interest, nets income against expenses, and routes surplus cash to your designated account. The result is a projection that shows exactly when you cross your FIRE target — and what happens after.
Unlike spreadsheets, you don't have to build the formulas. Unlike paid tools like ProjectionLab or Boldin, there's no subscription. Unlike apps that sync your bank accounts, your data never leaves your browser. Calculate your FIRE number first, then come back here to plan the path.
Key Features
9 Account Types
Track retirement accounts (401k, IRA), Roth accounts, HSA, taxable brokerage, high-yield savings, real estate equity, cash, cryptocurrency, and custom accounts. Each has a default growth rate you can override — model a rental property at 4% and a brokerage at 7% in the same profile.
Income & Expense Modeling
Six income types (salary, social security, pension, rental, side income, other) with start/end dates and growth rates. Eight expense categories with individual inflation rates — healthcare at 5%, housing at 3%, discretionary at 2.5%. Time-bound expenses model temporary costs like childcare or a mortgage that ends in 2038.
Retirement Drawdown
Three withdrawal strategies: tax-efficient (deplete taxable first), proportional (withdraw based on account share), or custom order. The 59.5 penalty-free age rule prevents early withdrawals from retirement accounts when other funds are available.
Stress Testing
Six scenarios: market crash (10-60% drop with recovery period), lower returns, income loss, expense spike, high inflation, and early/late retirement. See how your plan holds up under the conditions that keep you up at night.
Monte Carlo Simulation
Run 100-5,000 randomized return sequences to find your plan's success probability. Uses drift-corrected lognormal distribution with configurable annual volatility (default 15%, matching historical S&P 500). Results show percentile bands (p10 through p90) so you can see the range of outcomes, not just one line.
Historical Backtesting
Test your plan against every historical period from 1871 to present using Shiller S&P 500 monthly returns. If your plan would have survived 95% of all historical 50-year periods, you know it's robust. Includes a portfolio survival heatmap showing success rates across withdrawal rates and starting decades.
Cash Flow Visualization
A Sankey diagram shows where your money flows each year — income sources to expenses, debt payments, and asset contributions. Switch between accumulation and retirement phases, toggle monthly or annual view. A contributions vs. growth chart tracks when investment returns surpass what you put in.
Milestones & Tracking
Milestone badges at 25%, 50%, 75%, and 90% of your FIRE target. A stacked area chart shows every asset growing over time, with your target as a horizontal line and a vertical marker at your projected retirement date.
How to Get Started
- Set your basics. Enter your age, target retirement age, and monthly expenses. The planner calculates your FIRE number automatically.
- Add your accounts. Enter each investment account, savings account, and debt with current balances. Set growth rates or use the defaults.
- Model your income and expenses. Add your salary, any side income, and your expense categories. Set start/end dates for anything that isn't permanent.
- Review your projection. The chart and tables show your path to financial independence month by month. Use stress tests to see how your plan handles adversity.
For a detailed walkthrough, see the Fire Planner guide.
Frequently Asked Questions
Yes. All data is stored in your browser's localStorage. Nothing is sent to any server — there are no accounts, no sign-ups, and no tracking. Your financial information never leaves your device. We can't see your data even if we wanted to.
Projections use month-by-month compounding with individual growth rates per asset, per-debt interest accrual, and time-bound income and expense modeling. They're as accurate as your inputs and assumptions. The stress testing feature lets you model market crashes, lower returns, and inflation spikes to see how sensitive your plan is.
Yes. Create multiple profiles to model different scenarios — aggressive savings vs. conservative, early retirement vs. traditional, with or without a career change. Switch between profiles instantly. Each profile has its own complete set of assets, debts, income, and expenses.
Nine asset categories: Retirement Accounts (401k, IRA, 403b), Roth Accounts (Roth IRA, Roth 401k), HSA, Taxable Brokerage, High-Yield Savings, Real Estate Equity, Cash/Checking, Cryptocurrency, and Other. Each has a default growth rate you can override. You can also track liabilities with interest rates and payment schedules.
Yes. Export your profile as a CSV file that includes a full data backup. You can import it back on another device or browser. Since data lives only in your browser, regular exports are recommended as a backup.
Monte Carlo simulation tests your retirement plan against hundreds or thousands of randomized market return sequences. Instead of assuming a fixed 7% return every year, it models the uncertainty of real markets — some years up 20%, some down 15%. The result is a success probability: the percentage of simulations where your portfolio survived through retirement. A 90%+ success rate is generally considered robust.
Historical backtesting runs your exact financial plan against every overlapping historical period from 1871 to present, using actual S&P 500 returns from the Shiller dataset. If your plan would have survived 95% of all historical 50-year periods — including the Great Depression, stagflation, and the 2008 financial crisis — you have strong evidence it's resilient.