FIRE Calculator (Financial Independence, Retire Early)

4% is the canonical "safe" number from the Trinity Study, which tested historical 30-year retirement windows. More conservative planners use 3-3.5% for longer horizons or volatile portfolios. Aggressive ones use 4.5-5% if they're comfortable adjusting spending in down years. The right number for you depends on flexibility — if you can cut spending 10-20% in bad years without breaking, 4% is safe; if your expenses are mostly fixed, drop to 3.5%.

For most middle-class earners targeting traditional FIRE: a 50% savings rate gets you there in roughly 17 years; 30% in 28 years; 15% in 43 years. The math is brutal but mostly about time + savings rate, not investment selection. Run the Savings Goal Calculator with your FIRE number as the target to solve for the exact monthly contribution at any horizon.

Yes, with adjustments. The 4% rule is calibrated on US market history but holds reasonably well for diversified global portfolios. Tax-efficient wrappers differ wildly — UK has ISAs and SIPPs, Australia has super, Canada has TFSAs and RRSPs — and account for a large portion of FIRE math in those countries. Most non-US FIRE communities (UK r/FIREUK, Australian r/fireaustralia) maintain country-specific resources.

Yes, but conservatively. State pensions arrive at official retirement age, not at your FIRE date — so they cover the back half of your retirement, not the front. Reasonable approach: assume you'll get 70-100% of your projected pension (depending on how long until you receive it and your trust in the system), and let it offset spending after the official age. The first decade of FIRE is the part you have to fund entirely from your portfolio.

Geography-dependent. UK / NHS countries: largely solved, no extra cost. US: the hardest single FIRE problem — pre-Medicare (age 65) coverage runs $500-1500/month for an individual on ACA, varies by income and state. Many US FIRE practitioners model income to stay below ACA subsidy cliffs, or geo-arbitrage to lower-cost states or countries. Other countries: research the local system; insurance costs sit somewhere between UK and US extremes.

Lean FIRE: minimum-viable lifestyle, often <$40K/yr. Fat FIRE: comfortable / luxury, often $100K+/yr. Coast FIRE: enough invested that compounding alone gets you to traditional retirement — you cover only current expenses, no more saving needed. Barista FIRE: enough for essentials but keep a part-time job for healthcare/income smoothing. Set the inputs to match the variant you're aiming for.

More realistic than most assume — but it requires structural lifestyle changes, not just discipline. The combination of high savings rate (40%+) and decades of consistent investing has produced FIRE for tens of thousands of regular earners (teachers, engineers, nurses). The hardest part isn't the maths, it's the years of consumption deferral. Coast FIRE is much easier and gets most of the freedom benefit by your 40s rather than 30s.