Free · No login · Your withdrawal rate, not a fixed assumption
Early Retirement Calculator (FIRE) — Your Number, Your Timeline
Enter your real income, expenses, and current savings. Pick your own safe withdrawal rate instead of assuming the 4% rule fits everyone. See your FIRE number and the actual age you hit it.
How the FIRE Number Actually Gets Calculated
Your FIRE number is your annual expenses divided by your chosen safe withdrawal rate — the inverse relationship means a 4% withdrawal rate implies a number 25x your annual expenses, while a more conservative 3.5% implies roughly 28.5x. The "4% rule" comes from the Trinity Study, which tested historical 30-year US market returns and found a 4% initial withdrawal (adjusted for inflation each year after) survived nearly all 30-year periods without depleting the portfolio.
The 4% rule's biggest limitation for early retirees: it was tested against 30-year retirement horizons, but someone retiring at 35 might need the portfolio to last 50-60 years, not 30. This is the real argument for a lower withdrawal rate (3-3.5%) for genuinely early retirements — more time for sequence-of-returns risk (a bad market in the first few retirement years) to do lasting damage to a portfolio withdrawing too aggressively too early.
Savings rate, not income level, is the dominant variable in how fast someone reaches FIRE. A high earner spending nearly everything reaches FIRE slowly; a moderate earner saving 50%+ of income reaches it in roughly half the time of someone saving 25%, almost regardless of the income gap between them — because the FIRE number itself scales with spending, and a lower spending number compounds against a higher savings rate twice.
Is the 4% rule still considered safe in 2026?
It remains a widely-used baseline, but increasingly treated as a starting point rather than a guarantee — particularly for retirements expected to last 40+ years, where many planners now suggest 3-3.5% as a more conservative target, or a flexible-spending approach that adjusts withdrawals based on portfolio performance rather than a fixed inflation-adjusted amount every year regardless of market conditions.
Does this calculator account for Social Security?
No — this calculator treats your investable net worth as the sole source of retirement income, the standard conservative FIRE approach, since Social Security eligibility (age 62+) typically arrives well after an early retirement date and shouldn't be relied on for the gap years. Once you're closer to traditional retirement age, Social Security can reduce the portfolio withdrawal needed, effectively adding a safety margin not reflected here.
What's the difference between FIRE, Lean FIRE, and Fat FIRE?
These describe lifestyle targets, not different math: Lean FIRE targets a stripped-down expense level (often under $40,000/year), standard FIRE targets a comfortable-but-modest lifestyle, and Fat FIRE targets a higher, less-constrained spending level (often $100,000+/year). All three use the same withdrawal-rate math — only the annual-expenses input changes, which is exactly what you can test by adjusting the expenses field above.
How accurate are FIRE projections this far in advance?
Directionally useful, not precisely predictive — actual market returns, inflation, career changes, health events, and life changes will all deviate from any straight-line projection over a 10-20+ year horizon. Treat the projected age as a planning target to revisit and adjust annually as real results come in, not a fixed date to expect with confidence.
