✓ Reviewed for accuracy by the PayoutMath team — US sellers and creators who use these platforms · Last verified 25 April 2026

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FIRE Calculator US (Financial Independence, Retire Early)

FIRE = saving aggressively to reach a portfolio that supports your annual spending forever via a 4% safe withdrawal rate. $40,000/year spending → $1,000,000 FIRE number. Calculator below shows years to FIRE based on current savings, savings rate, and expected returns.

Last verified: 25 April 2026 Source: SEC investor.gov — retirement / FIRE planning resources Next review: 25 July 2026

Inputs

Annual spending in retirement ($)

Your expected yearly outgoings once retired. Lower = lower FIRE number.

Current investment portfolio ($)

Total invested across Roth IRA, 401k, HSA, taxable brokerage.

Annual savings/investment ($)

Amount you invest each year. Higher = faster FIRE.

Expected real return (%)

Real (above inflation). US historical equities: ~5%. Conservative: 4%. Aggressive: 6-7%.

Safe withdrawal rate (%)

Standard 4% rule. Some FIRE planners use 3.5% for safety, 4.5% for leaner plans.

FIRE number —

Years to FIRE —

Monthly savings —

Detail —

Lean FIRE — $30k spending

$30k spend · $50k portfolio · $15k/year savings · 5% real return · 4% withdrawal

FIRE number: $750,000 (= $30k ÷ 4%). At $15k/year savings + 5% real return + $50k starting, FIRE in ~22.5 years. Lean FIRE is achievable for above-average savers with modest spending targets.

Standard FIRE — $40k spending

$40k spend · $100k portfolio · $25k/year savings · 5% return · 4% withdrawal

FIRE number: $1,000,000. Strong 25k/year savings rate (likely high earner with frugal lifestyle) reaches FIRE in ~18.8 years. The 4% withdrawal rule supports $40k/year spending forever from $1M.

Fat FIRE — $60k spending

$60k spend · $200k portfolio · $40k/year savings · 5% · 4%

FIRE number: $1,500,000. Higher target spending requires either higher income ($40k saving from a $60k+ post-tax income) or longer timeframe. Fat FIRE typically takes 15-25 years from a strong starting point.

FIRE — Financial Independence, Retire Early — is the practice of saving aggressively until your portfolio is large enough that a 4% annual withdrawal covers your living expenses forever. The calculator above tells you your FIRE number and how many years it takes to get there.

The 4% rule

FIRE number = annual spending ÷ 4% = annual spending × 25

Annual spending	FIRE number (4%)	FIRE number (3.5%)
$20k (Lean FIRE)	$500,000	$571,000
$30k	$750,000	$857,000
$40k (Standard)	$1,000,000	$1,143,000
$60k (Fat)	$1,500,000	$1,714,000
$100k (Fat-Fat)	$2,500,000	$2,857,000

The maths behind years to FIRE

With starting portfolio P, annual savings S, and real return r, years to reach FIRE number F:

years = ln((S/r + F) / (S/r + P)) / ln(1+r)

The calculator handles this — useful intuition: - Higher savings rate = lower years (linear effect) - Higher returns = lower years (compound effect — more impactful long-term) - Lower spending target = double benefit (smaller F + ability to save more)

US-specific FIRE considerations

Roth IRA + 401k + HSA are US FIRE’s superpowers. Combined contribution limits ~$35k+/year tax-advantaged. Roth IRA ($7k) gives tax-free growth and flexible early access to contributions; 401k ($23.5k) gives upfront deduction + employer match; HSA ($4.3k self/$8.55k family) is triple-tax-advantaged for medical-then-anything-after-65.

Accessing tax-advantaged accounts before 59½. The standard 401(k)/traditional IRA early-withdrawal penalty (10% on top of ordinary income tax) applies before age 59½ — but two well-established mechanisms let early retirees route around it legally: a Roth conversion ladder (converting traditional 401k/IRA funds to a Roth IRA and waiting the mandatory 5-year seasoning period before withdrawing the converted principal penalty-free) and Substantially Equal Periodic Payments under IRS Rule 72(t) (a fixed, calculated withdrawal schedule that avoids the penalty entirely, at the cost of inflexibility once started). Both are core FIRE-community techniques specifically because ordinary retirement withdrawal rules assume a traditional retirement age, not an early-40s or early-50s exit.

Social Security provides a partial ground floor, later than most FIRE plans assume. Full retirement age is 66-67 depending on birth year (67 for anyone born 1960 or later), and eligibility requires 40 work credits — roughly 10 years of covered work history. The average monthly benefit is in the realistic range most FIRE calculators should use rather than assume away, though it varies significantly with lifetime earnings; claiming early at 62 permanently reduces the monthly amount, while delaying to 70 increases it. For most FIRE planners, Social Security is worth modeling as a later-life income supplement rather than a floor available from the moment of early retirement — it doesn't start until 62 at the earliest.

Real return assumptions

US historical equity real returns, commonly cited ranges: - S&P 500, long-run average: ~6.5-7% real (after inflation) - Global equities (60% US / 40% international): ~5.5% real - 60/40 stocks/bonds: ~3.5-4% real - All bonds: ~1-2% real

A commonly used planning assumption is 5% real return for an equity-heavy portfolio — deliberately more conservative than the long-run US equity average, to account for sequence-of-returns risk and the possibility that future returns underperform the historical record. Use 3-4% if you hold a significant bond allocation. Add roughly 2-2.5 percentage points on top for nominal-rate planning if your own spreadsheet works in nominal rather than inflation-adjusted terms.

What this calculator doesn’t model

Account type mix (Roth IRA vs traditional 401k vs HSA vs taxable brokerage — each has different withdrawal rules and tax treatment)
Early-withdrawal mechanisms (Roth conversion ladder, Rule 72(t) SEPP — see above)
Social Security (available from 62 at the earliest, full amount from 66-67 depending on birth year)
Sequence-of-returns risk (bad early years more harmful than bad late years, for an identical average return)
Healthcare costs before Medicare eligibility at 65 — a major, often underestimated cost for early retirees
Property (most FIRE planners exclude a primary home from portfolio value)
Inheritance / windfalls

For income tax planning during the accumulation phase, use the self-employment tax calculator if any of your income is 1099/self-employed. For long-term compounding math on taxable brokerage growth, see the compound interest calculator.

Common mistakes

Using nominal returns instead of real returns. US historical equity returns are ~7-9% nominal but ~5% real (above inflation). Use real returns in FIRE calculations because retirement spending grows with inflation.
Trusting the 4% rule blindly. The 4% rule is based on US data 1926-1995. Some US FIRE planners use 3.5% for safety, especially given US historic returns being slightly lower. The calculator allows you to adjust withdrawal rate.
Forgetting account-type order matters. US FIRE planning typically prioritizes maxing employer 401(k) match first (free money), then Roth IRA (currently $7k/year, tax-free qualified withdrawals), then further 401(k) or taxable brokerage. The calculator doesn’t model account-type structure directly — but the order you fill these matters for both employer match and long-term tax treatment.
Ignoring sequence-of-returns risk. A bad first 5 years of retirement (2008-style crash early) is much worse than a bad 5 years late in retirement. Some FIRE planners hold 2-3 years of cash buffer to avoid selling equities in downturns.
Not adjusting for healthcare costs before Medicare eligibility. US retirees under 65 have no Medicare access and must buy private insurance (ACA marketplace or COBRA), which can run several hundred to well over a thousand dollars per month depending on age, location, and coverage level. This is one of the single biggest underestimated costs in early-retirement FIRE plans — budget it explicitly rather than folding it into a generic spending estimate.
Treating FIRE as binary (work vs not work). Most FIRE achievers continue some part-time/passion work. ‘Coast FIRE’ (have enough that growth alone gets you there) and ‘Barista FIRE’ (enough for low-stress jobs to bridge) are intermediate stages worth modelling separately.
Underestimating discretionary spending. Most people understate retirement expenses. Build in 20-30% buffer above current spending to allow for travel, healthcare, helping family, unexpected expenses.

What this calculator doesn't cover

Doesn’t model the early-withdrawal penalty mechanics (Roth conversion ladder, Rule 72(t) SEPP) needed to access 401(k)/traditional IRA funds before age 59½.
Doesn’t differentiate Roth IRA vs traditional 401k vs taxable account tax treatment.
Doesn’t model sequence-of-returns risk or market crashes.
Single-input expected return; doesn’t account for stocks/bonds glide path adjustments.
Doesn’t model Social Security benefit amount (varies by lifetime earnings; full benefit from age 66-67, reduced from 62).
Doesn’t include inheritance, windfalls, or other lump-sum events.

Frequently asked questions

What's a 'FIRE number'?

The portfolio size at which a ‘safe withdrawal rate’ covers your annual spending forever. At 4% SWR: FIRE number = annual spending × 25. $30k/year spending → $750k FIRE number. $40k/year → $1M. $100k/year → $2.5M.

Is the 4% rule still valid?

It’s a US-based historical rule (1926-1995 data, Trinity Study). US and global data is mixed: 3.5-4% works in most historic periods. Many US FIRE planners now use 3.5% as a safety margin. Some use 4.5% for leaner FIRE accepting more risk. The calculator lets you adjust.

Roth vs traditional retirement accounts for FIRE?

Both have advantages. Roth IRA ($7k/year, 2025) gives tax-free growth and tax-free withdrawals after 59½ (or contributions earlier). Traditional 401k ($23,500/year, 2025) gives upfront tax deduction but withdrawals taxed as ordinary income. HSA ($4,300 self / $8,550 family) is triple-tax-advantaged with HDHP. Most US FIRE strategies: max HSA first (if eligible), then employer 401k match, then Roth IRA, then 401k up to limit, then taxable brokerage.

How does Social Security affect FIRE?

Social Security requires 40 work credits (roughly 10 years of covered work) and pays a full benefit from age 66-67 depending on birth year, with reduced benefits available from 62. The average benefit varies significantly with lifetime earnings history. Because it isn’t available until 62 at the earliest, most FIRE plans treat it as a later-life supplement rather than a source of income during the early-retirement years themselves.

What's Coast FIRE?

When your existing portfolio, with no further savings, will grow to your FIRE number by your target retirement date. $100k at age 30 with 5% real return reaches $700k by 60 — ‘coasting’ to FIRE without saving more. Useful intermediate goal: stop saving aggressively but keep working to cover current spending.

Should I include my main home?

Most FIRE planners exclude primary residence from the FIRE number — you live in it, can’t easily extract cash. Some include rental properties or planned downsizing equity. Be conservative with property values; equity is real but illiquid.

What if I want to retire abroad?

Lower-cost-of-living countries can dramatically reduce FIRE number. $40k/year US lifestyle might cost $20k in Spain or $15k in Portugal. Geographic arbitrage is the highest-leverage FIRE accelerator. US citizens remain liable for US tax on worldwide income regardless of where they live, so overseas retirement doesn't remove US tax filing obligations \u2014 check the specific tax treaty and foreign earned income exclusion rules for the destination country.

About this calculator. Maintained independently — a US-based seller and creator who actually uses these platforms (Etsy, eBay, Amazon). Built to be accurate, mobile-fast, and honest about its limits. Spot a bug? Email hello@payoutmath.com.

The two resources most useful alongside this calculator: a FIRE investing guide covers the 4% rule and safe withdrawal rate mechanics behind the numbers, and an expense tracker is the honest starting point — and often the shock — that makes the FIRE calculation concrete.