FIRE Number Calculator

Find your Financial Independence, Retire Early target and see exactly how long it will take to get there.

Your FIRE Inputs
Enter a valid annual expense amount.
4.0%
Enter a rate between 0.1% and 20%.
Enter 0 or a positive number.
Enter 0 or a positive number.
7.0%
Enter a rate between 0.1% and 50%.
3.0%
Enter a rate between 0% and 20%.
Enter an age between 1 and 100.
Your FIRE Number
โ€”
Amount needed to retire early
Portfolio at FIRE Date
Current SavingsInvestment GrowthContributions
Year-by-Year Projection
Year Age Contributions Portfolio Value FIRE %
FIRE Scenarios Comparison

How to Use This FIRE Number Calculator

Enter your expected annual expenses in retirement, your current savings, and how much you save each year. Adjust the withdrawal rate (the default 4% is based on the Trinity Study), your expected investment return, and inflation. Hit "Calculate" and you'll instantly see your FIRE number, the years to reach it, and a year-by-year portfolio projection.

Why This Matters

FIRE โ€” Financial Independence, Retire Early โ€” isn't just for the ultra-wealthy. A 30-year-old spending $50,000/year needs a $1,250,000 portfolio at the 4% rule. That sounds huge, but saving $2,000/month in an index fund averaging 7% annually gets you there in roughly 22 years โ€” by age 52, without a trust fund or lottery win.

The magic is understanding your exact target. Without a number, you're guessing. Once you know you need $1.25M, everything changes: you can optimize your savings rate, consider geographic arbitrage, cut unnecessary expenses, or pick up a side hustle to shave years off your timeline. People who calculate their FIRE number consistently save more and retire earlier than those who don't โ€” because a concrete goal creates concrete action.

Different people pursue different flavors: Lean FIRE targets a minimalist ~$40K/year budget, Regular FIRE maintains your current lifestyle, Fat FIRE targets $100K+ in annual spending, and Coast FIRE is when your portfolio is already large enough to grow to your FIRE number by retirement age without any new contributions.

How It's Calculated

The FIRE number is derived from the Safe Withdrawal Rate (SWR), established by the Trinity Study:

FIRE Number = Annual Expenses รท Withdrawal Rate

For example: $50,000 รท 0.04 = $1,250,000. The year-by-year projection compounds your existing portfolio and adds annual contributions at the real rate of return (nominal return minus inflation). The Coast FIRE number calculates how much you need invested today so compound growth alone โ€” without future contributions โ€” reaches your FIRE number by a target retirement age.

Portfolio(n) = Portfolio(n-1) ร— (1 + r) + Annual Contribution

Where r = (1 + nominal return) รท (1 + inflation) โˆ’ 1 (real return). All projections use real (inflation-adjusted) dollars so the result is directly comparable to today's purchasing power.

Tips & Common Mistakes

Frequently Asked Questions

What is the 4% rule and is it still valid?

The 4% rule comes from the 1994 Trinity Study, which analyzed historical 30-year retirement periods and found that withdrawing 4% of your initial portfolio annually (adjusted for inflation) survived 95%+ of scenarios. It remains a widely used baseline, though some planners recommend 3โ€“3.5% for retirements longer than 30 years, and others argue 5% is fine with flexible spending.

What return rate should I use?

The US stock market has averaged roughly 10% nominal returns historically. After a 3% inflation adjustment, that's ~7% real. For a diversified portfolio with some bonds, 6โ€“7% real is a common conservative assumption. Avoid being too optimistic โ€” even a 1% difference in assumed returns can shift your FIRE date by several years.

What's the difference between FIRE and Coast FIRE?

Regular FIRE means your portfolio is large enough to fund your retirement today. Coast FIRE means you've saved enough that โ€” even without any more contributions โ€” compound growth will get you to your FIRE number by a traditional retirement age. Once you hit Coast FIRE, you can stop saving aggressively and just cover your living expenses.

Does Social Security factor in?

This calculator focuses on your investment portfolio target and doesn't include Social Security income. If you expect Social Security benefits, subtract your estimated annual benefit from your annual expenses before entering the number โ€” this will reduce your required FIRE number meaningfully, especially for those retiring at 50+.

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