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 to 50 years or more. Every month, it compounds each asset at its own rate, applies contributions, accrues debt interest, nets income against expenses, and puts unspent income into the account you pick. The result is a date: the month you can retire, graded three ways, and what happens to your money after it.
The formulas are built in. ProjectionLab and Boldin are paid tools. This planner has no subscription. There is no account to create. Nothing links to your bank. Your data never leaves your browser. Calculate your FIRE number or get a quick date from the FIRE calculator first, then come back here to plan the path. Prefer to keep your own offline record? The FIRE tracker spreadsheet logs the same monthly progress in Excel or Google Sheets.
Key features
When you can retire, graded three ways
The answer is one line: "Retiring Oct 2042, at 48". Three models grade it side by side. Average returns runs your plan at steady growth. Monte Carlo runs it through 500 simulations by default. The historical backtest runs it through every start year since 1872. Each one says whether your money lasts and what you have at retirement, in today's money or in future money.
Nine account types
Track retirement accounts (401(k), IRA), Roth accounts, HSA, taxable brokerage, high-yield savings, real estate equity, cash, crypto and other accounts. Each has a default growth rate you can override: model a rental property at 4% and a brokerage at 7% in the same plan.
Income and expenses
Six income types (salary, Social Security, pension, rental income, side income, other) with start and end dates and growth rates. Eight expense categories, each growing with your inflation rate plus its own offset: healthcare at 5%, housing at 3%, fun at 2.5% when inflation is 3%. Time-bound expenses model temporary costs like childcare or a mortgage that ends in 2038.
Retirement drawdown
Three withdrawal orders: taxable first (taxable, savings and cash, then retirement and HSA, then Roth, then real estate, crypto and other), proportional (withdraw based on account share), or a custom order. Turn on the early withdrawal penalty (before age 59.5, adjustable) and withdrawals stay out of retirement, Roth and HSA accounts before that age unless nothing else is left.
Stress tests
Six tests: a market crash (a drop of 1 to 95%, then slower growth), lower returns, income loss, a spending spike, high inflation, and retiring earlier or later (two years early by default, as if you had to stop work). Tick one and the answer includes it.
Monte Carlo simulation
Run 100 to 5,000 simulations (500 by default) and see how many your money lasts in. Each one draws its yearly returns from a drift-corrected lognormal distribution, with yearly swings you set (15% by default, about the S&P 500's historical level). The chart shows the middle 50% and 80% of simulations around the median, so you see the range of outcomes.
Historical backtest
Test your plan against every start year since 1872 using Shiller S&P 500 monthly returns, and see how many it lasts in. Below it, a Trinity Study-style table ("Survival by start year") shows how often a 100% stock portfolio lasted at withdrawal rates from 3% to 6%, by decade.
The evidence
Four tabs show why the answer is what it is. Path draws your net worth year by year for the model you picked. Money flow is a Sankey diagram of one year: income paying for spending, debt payments and savings while you work, and the accounts you draw on once you retire. Saved vs growth splits what you will have into what you put in and what growth adds. Table lists the plan year by year.
What moves it, check-ins and plans
"What moves it" shows what spending 10% less, retiring 3 years later or earning and saving 500 a month more would do to the answer. "Could you stop saving today?" answers the coast question. Each check-in is measured against your plan as you first set it up ("$4,200 ahead of plan"). Keep up to 5 named plans and compare them in one table.
How to get started
- Answer five questions. Your age, invested savings, monthly spending, monthly income, and when you want to retire: as early as possible, or in a year you pick. The answer appears at once.
- Read the answer. Pick a model card to see its numbers and the evidence under it. Tick a stress test to see what a crash or a lost job does to the date.
- Make the plan yours. Add your real accounts, debts, income and expenses in the inputs, each line in its own form. An income, spending or investment line you add comes out of the totals you typed, so they stay the same. "Complete your plan" lists what is left.
- Check in. Once a month, record your balances in Check-ins. The newest check-in says how far ahead of or behind your plan you are.
For a detailed walkthrough, see the Fire Planner guide.
Frequently asked questions
Yes. Everything you enter stays in your browser's localStorage. There are no accounts and no sign-ups. We don't store your numbers anywhere and can't see them.
The site does use analytics. Cloudflare Web Analytics runs on every visit and sets no cookies. Google Analytics and Microsoft Clarity also run. In the EU, EEA, UK and Switzerland, Google Analytics sets no cookies and Clarity doesn't load until you accept the cookie banner. Details in the privacy policy.
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. Stress tests show what a market crash, lower returns or an inflation spike does to your plan.
Yes, up to 5 plans. The plan menu in the top bar shows your plan's name ("My plan" at first). Use it to duplicate your plan or start a new one from its numbers, change what you want to test (retire at 50 instead of 55, a career change, a lower savings rate) and switch back and forth. Each plan keeps its own assets, debts, income, expenses, settings and check-ins. Compare plans puts them in one table: when each one retires, whether the money lasts on average returns, how many Monte Carlo simulations and historical start years it lasts in, and net worth at retirement. All plans are stored in this browser, with no account, so they don't follow you to another device. File ▸ Export plan (CSV) backs up the plan you have open.
Nine account types: Retirement account (401(k), IRA, 403(b)), Roth (Roth IRA, Roth 401(k)), HSA, Taxable brokerage, High-yield savings, Real estate equity, Cash, Crypto and Other. Each has a default growth rate you can override. Debts take a balance, an interest rate and a monthly payment.
Yes. File ▸ Export plan (CSV) downloads the plan you have open: your check-ins as rows a spreadsheet reads, and a backup of the whole plan. File ▸ Import plan (CSV)… reads it back on another device or browser, in place of a plan or as a new one. Your plans live only in this browser, so export now and then as a backup.
Monte Carlo simulation tests your retirement plan against hundreds or thousands of simulated markets. Each simulation draws a different return every year: some years up 20%, some down 15%. The planner runs 500 simulations by default (100 to 5,000) and counts the ones where your money lasts to your "Money must last until" age: "money lasts in 462 of 500 simulations". It also shows how the best and worst 10% of simulations end.
Historical backtesting runs your exact financial plan through every start year since 1872, using actual S&P 500 returns from the Shiller dataset. The result counts the start years your money lasts in, such as "money lasts in 82 of 96 start years". Those years include starts just before the Great Depression, 1970s stagflation and the 2008 financial crisis.