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. Prefer to keep your own offline record? The FIRE tracker spreadsheet logs the same monthly progress in Excel or Google Sheets.
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: 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 custom order. The penalty-free age rule (59.5 by default, adjustable) keeps withdrawals out of retirement, Roth and HSA accounts before that age unless nothing else is left.
Stress Testing
Five scenarios: market crash (1-95% drop with recovery period), lower returns, income loss, expense spike, and high inflation. 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 95% of historical periods lasted to your end year, you know the plan is robust. Below it, a Trinity Study-style heatmap shows how often a 100% stock portfolio lasted at withdrawal rates from 3% to 6%, by starting decade.
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.
Your FI Date, Milestones & Plans
The headline answers "when can I retire?" with the earliest month your money lasts to your end year, and one click makes it your retirement date. Milestones at 25%, 50%, 75%, and 90% of your FIRE target sit under the progress bar with the next one named. Each check-in is measured against your plan as you first set it up ("$4,200 ahead of plan"), and the chart draws that plan as a dashed line. Keep up to 5 named plans and compare them in one table.
How to Get Started
- Set your basics. Enter your age, invested savings, monthly spending and monthly net income. The planner sets your FIRE number to 25x annual spending and starts your plan at the earliest date it works; change either later.
- 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. 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. The stress testing feature lets you model market crashes, lower returns, and inflation spikes to see how sensitive your plan is.
Yes, up to 5 plans. Open the "My plan" menu to duplicate your plan, 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 puts them in one table: earliest FI date, net worth at the end year, and whether the money lasts. All plans are stored in this browser, with no account, so they don't follow you to another device. Export CSV backs up the plan you have open.
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 reads like "92% of simulations lasted to 2070": the share of runs where your money lasted to your end year. 90% or more 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 95% of historical periods lasted to your end year, including starts just before the Great Depression, stagflation, and the 2008 financial crisis, you have strong evidence it's resilient.