Using the Fire Planner

firenum team · Last updated February 8, 2026

Why Track Your FIRE Progress

Financial independence isn't a single moment—it's a gradual shift. Tracking makes that shift visible. It turns "I want to be financially independent" into "I'm 42% of the way to $1,200,000."

Regular tracking makes goals concrete, reinforces saving habits, prevents lifestyle inflation from eating your progress, and catches problems (like debt growing faster than payments) before they become expensive. You don't need to obsess over daily market movements. But ignoring your finances entirely means you won't notice problems until they're hard to fix.

Setting Up Your Profile

The Fire Planner builds a complete picture of your finances: assets, debts, income, expenses, and one-time events. Everything lives in your browser—nothing is sent to any server.

Birth Date & Retirement Date

Your birth date drives age calculations throughout the projection. It's especially important for the 59.5 penalty-free age rule—the engine uses it to determine when you can access retirement accounts without penalty.

Your retirement date is when the engine switches from accumulation mode (contributions in, surplus deposited) to withdrawal mode (drawing down assets to cover expenses). Income streams set to "ends at retirement" will stop on this date.

Setting Your FIRE Target

Your FIRE target is the net worth you're working toward. Click the target value to edit it. If you've already used one of the calculators, the tracker can bootstrap from that result. The target drives your milestone percentages (25%, 50%, 75%, 90%) and shows as a horizontal line on the projection chart.

Adding Assets

Add each investment account, savings account, or property you want to track. The tracker supports 9 asset types, each with a sensible default growth rate:

Each asset has a "Use market rate" toggle. When on, the asset uses your global default growth rate (7% by default). Turn it off to set a custom rate—useful for savings accounts, real estate, or crypto where you want a different assumption.

You can also set a monthly contribution for each asset and enable/disable individual assets without deleting them.

Adding Liabilities

Add debts with a balance, interest rate, and monthly payment. The engine accrues interest monthly, then applies your payment. If your payment doesn't cover the monthly interest, the tracker will show a health warning—that debt will grow forever.

Debts also have a projected payoff date based on your payment amount, visible in the projection tables.

Adding Income Streams

Income streams represent money coming in. Each has a type, amount, frequency (monthly or annual), optional start/end dates, and an annual growth rate:

Set the end date to "Ends at retirement" for income that stops when you retire (like salary). Use explicit dates for income that starts later (like Social Security at 67).

Adding Expenses

Expenses inflate over time. Each category has its own default inflation rate because healthcare costs rise faster than groceries:

Like income, expenses support time bounds (start/end dates), monthly or annual frequency, and custom inflation rates per item. If you add expenses, the engine uses them to calculate your suggested FIRE number (annual expenses × 25).

One-Time Events

One-time events model windfalls or large expenses that happen on a specific date. Positive amounts are inflows (inheritance, bonus, home sale), negative amounts are outflows (wedding, home purchase, medical bill).

You can optionally target a specific asset for the event. If no target is set, the event applies to your designated surplus asset. Events are applied during the projection at the month they occur.

Running Projections

Projections run automatically whenever your data changes. The engine simulates every month from now until 50 years out (configurable), applying growth, contributions, debt payments, income, expenses, and withdrawals. For the exact math, see How Projections Work.

Reading the Chart

The projection chart shows a stacked area graph of your assets over time. Each asset type is a different color, stacked to show your total portfolio composition. Key markers:

• FIRE target line—horizontal line at your target net worth
• Retirement line—vertical line at your retirement date
• Net worth line—your total net worth trajectory (assets minus liabilities)
• Milestone markers—25%, 50%, 75%, 90% progress points

Projection Tables

Below the chart, five tabs break down the numbers:

• Summary—yearly net worth, growth, and milestone tracking
• Assets—per-asset balances, growth, contributions, and surplus deposits
• Liabilities—per-debt balances, interest, and payments
• Cash Flow—income, expenses, surplus, and net cash flow by month
• Withdrawals—which accounts are drawn from during retirement, amounts, and early withdrawal flags

Advanced Analysis

The standard projection shows what happens if growth rates stay constant. Real markets don't work that way. The analysis mode selector (above the projection chart) lets you switch between three modes to stress-test your plan against randomness and history.

Monte Carlo Simulation

Instead of one fixed-growth projection, Monte Carlo runs hundreds or thousands of randomized scenarios. Each run applies a different sequence of monthly returns drawn from a lognormal distribution, so you see the range of possible outcomes instead of a single line.

Two settings to configure:

• Simulations—how many runs (100–5,000). More runs = smoother results, but takes longer. 1,000 is a good starting point.
• Annual Volatility—how much returns swing year-to-year (1–40%, default 15%). 15% matches historical S&P 500 volatility. Increase it for a more aggressive stress test.

The result chart shows percentile bands (P10, P25, P50, P75, P90) of your portfolio value over time. The success rate tells you what percentage of runs survived without depleting your portfolio. Only market-rate assets get randomized—assets with custom growth rates keep their fixed returns.

Click "Run Simulation" to start. Results clear automatically when you change any input. For the math behind it, see Monte Carlo calculations.

Historical Backtesting

Backtesting answers: "Would my plan have survived every historical period since 1871?" It replays your exact profile against real S&P 500 monthly returns from the Shiller dataset—roughly 1,260 overlapping periods for a 50-year projection.

The result chart shows the same percentile bands as Monte Carlo, plus labels for the worst-case and best-case starting years. A 90% success rate means your plan would have survived in 90% of all historical starting years.

No configuration needed—just click "Run Backtest".

Portfolio Survival Heatmap

The heatmap appears alongside backtest results. It's a Trinity Study-style grid showing whether a portfolio survived across different withdrawal rates (3.0%–6.0%) and historical starting years. Green cells survived, red cells depleted. Uses a colorblind-safe palette.

This gives you a quick visual answer to "how safe is my withdrawal rate?" across 150+ years of market data.

Contributions vs Growth Chart

Always visible below the projection chart, regardless of analysis mode. A stacked area chart showing two components of your portfolio over time:

• Contributions—money you put in (monthly contributions + surplus deposits)
• Growth—money the market generated (compound returns)

The chart annotates the crossover point—the year when cumulative growth exceeds cumulative contributions. After this point, the market has made you more money than you've invested. For most people at 7% growth, this happens around year 10–15.

Sankey Cash Flow Diagram

The Sankey diagram visualizes where your money flows in any given projection year. Select a year with the year picker, and toggle between monthly and annual views.

During accumulation, the diagram shows income sources flowing into expenses, debt payments, asset contributions, and surplus. During retirement, it flips: asset withdrawals and any remaining income flow into expenses and debt payments.

If your tracked income doesn't cover all outflows, the diagram adds an "Untracked Income" source to balance the flows—representing income you haven't explicitly modeled (spouse, side gigs, etc.).

Stress Testing Your Plan

A plan that only works in perfect conditions isn't a plan. The stress testing panel (available in Standard analysis mode) lets you toggle six scenarios to see how your finances hold up under pressure. Each scenario modifies the projection independently—enable as many as you want simultaneously. For the exact formulas, see stress test calculations.

Market Crash

Question it answers: What if the market drops 30% in 2 years?

Simulates an immediate percentage drop in risky assets (stocks, real estate, crypto) at a specified year (0–50), followed by a recovery period (1–50 years) with reduced growth. Drop severity ranges from 1–95%. Cash and savings accounts are protected. Defaults: 30% drop in year 2, 5-year recovery.

Lower Returns

Question it answers: What if the next few decades underperform historical averages?

Permanently subtracts a percentage (0–15%) from every asset's growth rate and the global default rate. A 2% reduction turns 7% growth into 5%. Default: reduce by 2%.

Income Loss

Question it answers: What if I lose all income in 3 years?

Zeroes out all income streams starting at the specified year (0–50). Permanently. This is a worst-case scenario for job loss without replacement. Default: income stops in year 3.

Expense Spike

Question it answers: What if my expenses jump 50%?

Multiplies all expenses by a percentage increase (1–500%) starting at the specified year (0–50). Permanent from that point forward. Useful for modeling a health crisis, new dependents, or relocation. Defaults: +50% in year 2.

High Inflation

Question it answers: What if inflation spikes to 6% for 3 years?

Overrides the default inflation rate (1–30%) for a time-limited window (1–20 years), starting 0–30 years out. Unlike other stress tests, this one ends—inflation returns to your base rate after the duration. Defaults: 6% inflation starting immediately, lasting 3 years.

Retire Earlier or Later

Question it answers: What if I retire 5 years earlier? Or 5 years later?

Shifts your retirement date by -20 to +30 years. Negative values mean earlier retirement, positive means later. This directly changes when the engine switches from accumulation to withdrawal mode. Default: 0 years (no change).

Withdrawal Strategies

Once you pass your retirement date, the engine needs to decide which accounts to pull from. The withdrawal strategy controls the order. For the exact calculations, see retirement withdrawal calculations.

Tax-Efficient (Default)

Depletes accounts in a tax-optimized order, one at a time:

1. Taxable accounts (brokerage, savings, cash)
2. Traditional retirement accounts (401k, IRA, HSA)
3. Roth accounts (Roth IRA, Roth 401k)
4. Everything else

The idea: spend taxable money first, let tax-advantaged accounts compound as long as possible, and save Roth (tax-free) for last.

Proportional

Withdraws from all eligible accounts simultaneously, proportional to their balance. If your brokerage holds 60% of your total and your 401k holds 40%, withdrawals are split 60/40. This keeps your asset allocation roughly constant through retirement.

Custom Order

Drag and drop your accounts into your preferred withdrawal sequence. The engine drains them in your specified order, one at a time. Use this if you have a specific strategy (e.g., drain a particular account first for tax bracket management).

The 59.5 Rule

When enabled, the engine skips retirement accounts (401k, IRA, Roth, HSA) if you're younger than 59.5. It withdraws only from non-retirement accounts first. If those run dry and you still need money, it pulls from retirement accounts anyway and flags those withdrawals as early withdrawals in the projection tables—a warning that real-world penalties would apply.

This matters most for early retirees. If you're retiring at 45, you need enough in taxable accounts to bridge the gap until 59.5.

Tracking Over Time

Check-Ins

A check-in is a snapshot of your actual balances at a point in time. Click "+ Check-In" to record current values for any asset or liability. The tracker shows the delta (change) from each entity's previous balance and the total after the update.

You can backdate check-ins if you forgot to log one. History is displayed in reverse chronological order, and individual entries can be deleted.

Recommended frequency: Monthly, on the same day. Consistent timing makes trends visible. Quarterly works if you prefer less maintenance.

Milestones

The tracker uses a 25-50-75-90% framework based on your FIRE target. Each milestone represents a psychological shift:

• 25%—Foundation: Real momentum. The hardest part (starting) is behind you.
• 50%—Halfway: Your investments earn roughly as much as you contribute. FIRE starts feeling inevitable.
• 75%—Coast territory: Even without new contributions, compound growth could carry you to FI. You have options. (What is Coast FIRE?)
• 90%—Final stretch: One good market year could push you over. Start planning what you'll actually do when work becomes optional.

Health Warnings

The tracker monitors your data for mathematical inconsistencies and flags them automatically. Warnings don't block anything—they're informational. There are five types:

You can dismiss individual warnings or dismiss all at once. Dismissed warnings automatically reappear after 7 days or when the underlying data changes. Warnings also auto-clear when you fix the issue (e.g., increase a debt payment above the interest amount).

Sharing, Export, and Import

Shareable Snapshots

Click Share to generate a URL that encodes your entire profile. The link uses base64 encoding—no data is stored on any server. Anyone who opens the link sees your profile in sandbox mode: a read-only view where they can explore the projections and charts without affecting their own data.

Sandbox visitors can save the snapshot to their own profile if they want to use it as a starting point. This replaces their existing data.

CSV Export

Export your check-in history as a CSV file. The export includes a date, entity name, type, previous balance, new balance, change, and total after each check-in. It also embeds a full backup of your profile data as a base64-encoded section at the bottom of the file.

CSV Import

Import a previously exported CSV file to restore your profile. The import reads the embedded backup section and replaces all existing data. You'll see a confirmation prompt before anything is overwritten. The validator checks that the backup contains at minimum an assets array and check-ins array.

Clearing Data

The Clear All Data button deletes everything—assets, liabilities, income, expenses, events, check-ins, and settings. You'll see a confirmation prompt. This cannot be undone. The page reloads after clearing to reset all state.

FAQ

How often should I check my FIRE progress?

Monthly works for most people. Frequent enough to catch issues and reinforce saving habits, infrequent enough to avoid obsessing over market swings. Quarterly is fine if you prefer less maintenance. The key is consistency—pick a schedule and stick to it.

Is my data private?

Yes. All data stays in your browser's localStorage. Nothing is sent to any server. Your financial data never leaves your device. Shareable snapshots encode data in the URL itself—still no server involved.

Should I include my home equity?

Only if you plan to access it in retirement. Downsizing or reverse mortgage? Include it as a Real Estate Equity asset. Living there forever? Leave it out—it won't generate retirement income. Many people track "investable assets" and "total net worth" as separate profiles.

What if the market crashes and my balance drops?

Log the real number. Tracking through downturns shows your true progress over time and reminds you that you kept investing through tough periods. Use the stress testing feature to see how a crash would affect your long-term plan before it happens.

Can I track a shared/joint portfolio with my partner?

Yes. Add all joint accounts as separate assets. The tracker doesn't care who owns what—it sums everything toward your shared FIRE target. For separate tracking, use different browsers or browser profiles.

What happens if I change my FIRE target?

All milestone percentages recalculate immediately. Your check-in history stays the same (balances don't change), but your progress percentage shifts. This is expected—life circumstances change and your target should reflect that.

How do shareable snapshots work?

Click the Share button to generate a URL that encodes your entire profile as a base64 string. Anyone with the link sees your profile in read-only sandbox mode. No data is stored on any server—the profile lives entirely in the URL. Recipients can save the snapshot to their own browser if they want to use it as a starting point.

The Fire Planner is designed to be as simple or detailed as you need. Start with a few assets and your FIRE target. Add income, expenses, and stress tests as you get comfortable. The projections get more useful the more context you give them.

→ Open the Fire Planner
→ How the math works: projection formulas and defaults
→ Calculate your FIRE number
→ New to FIRE? Start with the basics