FIRE Calculator: Your FI Number & Years to Financial Independence

Your FIRE number (FI number) is the total portfolio value that, once reached, can fund your lifestyle indefinitely via the 4% safe withdrawal rule. Formula: FI Number = Annual Spending × 25. Examples: $40,000/year → $1,000,000; $60,000/year → $1,500,000; $100,000/year → $2,500,000. The 25× multiple comes directly from inverting 4%: 1 ÷ 0.04 = 25. If you prefer a more conservative withdrawal rate of 3.5%, use a 28.6× multiplier instead.

The 4% rule originated in the 1998 Trinity Study by Cooley, Hubbard, and Walz, which analyzed historical US market data from 1926-1995 and found that a 4% withdrawal rate (adjusted annually for inflation) had ~95% historical success over 30-year retirement periods with a balanced stock/bond portfolio. In 2026 it remains the most widely-cited benchmark, though some researchers like Wade Pfau and the Big ERN blog argue the forward-looking success rate may be lower given elevated valuations. For 40-50 year FIRE horizons (early retirees), a 3.5% rate (28.6× FI multiple) is a more conservative and commonly recommended floor.

The timeline depends almost entirely on your savings rate — the percentage of take-home income you invest — not your absolute income. At a 50% savings rate with 7% returns, you reach FIRE in approximately 17 years from $0. At 70% savings rate, roughly 8-9 years. At 10%, over 40 years. The math: higher savings rate means both more invested and lower spending target (smaller FI number), compressing the timeline from both ends. The Mustachian Post and Mr. Money Mustache's original analysis (2012) popularized this insight and it remains mathematically correct.

Include: brokerage accounts (taxable), 401k/403b/457 (pre-tax), Traditional IRA, Roth IRA and Roth 401k, SEP-IRA/SIMPLE IRA, HSA balance invested (if used as a retirement account). Exclude unless you plan to sell: primary home equity, cars, business equity not easily liquidated. The 4% rule assumes liquid, income-producing assets — stocks and bonds you can sell or that produce dividends. Home equity does not generate income unless sold or reverse-mortgaged, so it counts only if downsizing is part of your FIRE plan.

For conservative planning: 5-6% nominal (equivalent to 2-3% real after inflation). For standard planning: 7% nominal (~4% real), which approximates the long-run historical return of a diversified 60/40 stock-bond portfolio after inflation. The S&P 500 has averaged ~10% nominal over 20-year periods, but a diversified portfolio with bonds and international stocks typically returns 7-8%. Avoid extrapolating recent exceptional returns (2010-2021 or 2023-2024 bull runs) into your 20-40 year planning horizon.

Coast FIRE is reached when your current portfolio, without any further contributions, will compound to your full FI number by traditional retirement age (65). Once you hit Coast FIRE, you only need to cover current expenses — you can stop aggressive saving and work in lower-stress or lower-paying roles. Example: at age 35 with $250,000 invested at 7% return, your portfolio grows to $250,000 × (1.07)^30 = ~$1,904,000 by age 65 — enough to support ~$76,000/year. If that's your spending target, you've hit Coast FIRE. This calculator's timeline assumes ongoing contributions; subtract those contributions mentally to check your Coast FIRE milestone.

Sequence-of-returns risk is the danger that poor market returns in the first 5-10 years of retirement permanently deplete your portfolio, even if long-run average returns match expectations. A 40% stock market drop at age 40 (versus age 60) gives your portfolio 25 fewer years to recover. The 4% rule historically survives most sequences, but the worst historical start dates (1966, 2000 peaks) were close to failing at 4%. Mitigation: (1) keep 1-3 years of living expenses in cash or short-term bonds; (2) build in spending flexibility — cut 10-15% in bad years; (3) have a small part-time income fallback for the first 5 years (Barista FIRE).

Both approaches give the same result if done consistently. Nominal returns (7-10%) with nominal spending growth (your future spending grows with inflation): use 7-8% return and let spending increase by 2-3%/year in your projections. Real returns (4-7%) with constant spending in today's dollars: use 4-5% return and keep spending flat. This calculator uses nominal returns. For a quick cross-check: real return = nominal rate − inflation rate. If you assume 7% nominal and 3% inflation, your real return is ~4%, and the FI number calculated in today's dollars is accurate.

Yes — include all retirement and brokerage accounts in your portfolio total. However, note that traditional 401k/IRA withdrawals before age 59½ trigger a 10% penalty (with some exceptions via SEPP/72(t) rules, Roth conversion ladders, or the rule of 55 for 401k). Many FIRE practitioners use a Roth conversion ladder: convert traditional IRA funds to Roth each year (paying taxes now at low marginal rates), then withdraw those contributions tax-free after 5 years. Taxable brokerage accounts have no age restrictions and long-term capital gains rates are 0-20%. Account type doesn't change the FI number calculation, but it affects tax strategy significantly.

Include all recurring annual expenses you expect in retirement: housing (rent/HOA/property tax/insurance), food, transportation, healthcare (most critical for early retirees — budget $10,000-$20,000/year per family before Medicare at 65 unless ACA subsidies apply), travel, entertainment, clothing, personal care, and discretionary. Common underestimates: healthcare, home maintenance (budget 1-2% of home value annually), car replacement (divide expected cost by years of useful life), and taxes on withdrawals from traditional accounts. Build in a 10-15% buffer above your current spending — lifestyle creep is real, and early retirement spending often increases before it plateaus.

Yes, completely free — no registration, no paywall, no data required. All calculations run entirely in your browser; no numbers you enter are sent to any server or stored in any database. Hacé Cuentas does not sell user data. Anonymous usage analytics (page views, calculator popularity) are collected via GA4, but these do not include the financial values you enter. Use this tool as often as needed for planning scenarios — there's no rate limit.

Lean FIRE: annual spending under $40,000, portfolio typically under $1M, minimalist or geo-arbitrage lifestyle. Regular FIRE: $40,000-$100,000/year spending, $1M-$2.5M portfolio, standard middle-class lifestyle. Fat FIRE: over $100,000/year spending, $2.5M+ portfolio, travel, premium housing, unconstrained discretionary. Barista FIRE: semi-retirement with a small part-time income (originally inspired by Starbucks' part-time health benefits) that supplements an undersized portfolio. Coast FIRE: your portfolio, left to compound without contributions, reaches your FI number by traditional retirement age — you can work any job that covers current expenses without adding to savings.

The calculator uses the compound future value formula with annual contributions: FV = Portfolio × (1+r)ⁿ + Contributions × ((1+r)ⁿ − 1)/r, where n = years and r = annual return rate. It solves numerically for the n at which FV equals your FI number (annual spending × 25). The result is the estimated years until your investments can sustain your lifestyle via the 4% rule. Key sensitivity: each additional $10,000 in annual contributions typically reduces the timeline by 1-3 years depending on current portfolio size and return rate.