Tool 15 of 30  ·  Investing

Your FIRE number is a specific, reachable target.

Enter your expenses, savings and return. See your FIRE number and inflation-adjusted timeline.

📐 Verified math
⚡ Instant results
🔒 No data stored
$0 Free
Your Parameters
Live
4% = Trinity Study benchmark
Your FIRE Number
calculating…
💡
What This Really Means
Adjust the sliders to see your personalised analysis.
Balance vs FIRE Target
Your balance
FIRE target
Full Breakdown
Annual expenses
Safe withdrawal rate
FIRE number
Current savings (progress)
Gap remaining
Time to FIRE (inflation-adjusted)
Nominal FIRE target at arrival

Common Questions

What is the 4% rule?
+
The Trinity Study (1998) found that a 4% annual withdrawal from a diversified portfolio has historically survived 30-year retirements ~95% of the time. It's a starting point, not a guarantee.
Why does this show more years than other calculators?
+
This tool correctly accounts for inflation: your FIRE number grows in nominal terms during accumulation (because your future expenses will be higher). Many calculators use a fixed target, which understates the timeline by several years.
What isn't modelled here?
+
Sequence-of-returns risk, Social Security income, healthcare costs in early retirement, and taxes on traditional 401k/IRA withdrawals. Use this as a directional guide, not a financial plan.
Download Your Full Report
Get your personalized analysis as a formatted PDF — your exact numbers, projections, and action steps.
Your exact calculator results & full breakdown
Projections and milestones timeline
Personalized action steps
Instant download — yours to keep
$9
One-time · Instant download
No subscription ever
🔒 Secured by Stripe · SSL encrypted
Disclaimer: For educational purposes only. Not financial advice. Projections use historical averages and are not guaranteed. Individual results will vary. Consult a qualified financial advisor before making financial decisions.

What Is the FIRE Number Calculator?

The FIRE Number Calculator tells you exactly how much money you need saved and invested before you can stop working permanently. It's designed for anyone pursuing Financial Independence, Retire Early — whether your target is 35, 45, or 55. Enter your expected annual expenses and the calculator shows the portfolio size that can sustain you indefinitely.

How the Calculation Works

Your FIRE number is calculated using the 4% rule, derived from the Trinity Study — a landmark 1998 analysis of historical stock and bond returns. The formula is simple: Annual Expenses ÷ 0.04 = FIRE Number. If you spend $50,000 per year, you need $1,250,000 invested. The 4% represents the safe withdrawal rate — the percentage of your portfolio you can withdraw annually without running out of money over a 30-year period.

Why This Number Matters

Knowing your FIRE number transforms retirement planning from vague aspiration into a concrete target. Once you know the number, every dollar saved becomes measurable progress toward that finish line. Studies show that people with a specific financial goal save 2–3x more aggressively than those without one — because the number makes the goal feel real and achievable.

Frequently Asked Questions

Is the 4% rule still valid in 2024?

The 4% rule remains the most widely used benchmark, but some financial planners now recommend 3–3.5% for retirements lasting 40+ years, due to lower expected bond returns. If you retire at 40, consider using 3.5% to build in a larger safety margin — that means multiplying annual expenses by 28.6 instead of 25.

Should I include Social Security in my FIRE number?

If you plan to claim Social Security, subtract your expected annual benefit from your annual expenses before calculating. Someone spending $60,000/year who expects $18,000 in Social Security effectively needs only $42,000/year from their portfolio — dropping the FIRE number from $1.5M to $1.05M.

What if my expenses change in retirement?

Most retirees follow a "smile" spending curve — higher spending early in retirement (travel, activity), lower in mid-retirement, then higher again in late retirement (healthcare). A practical approach: calculate your FIRE number at current expenses, then add a 10–15% buffer to account for this variability.

Related Calculators

Retirement Wealth Estimator → Compound Interest: Early vs Late → Investment Fee Drag Calculator →