Finance
Find your FIRE number and estimate how many years until your investments can cover your expenses.
| Age | Year | Balance | % of FIRE number |
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Your FIRE number is the amount of invested assets needed to sustainably cover your annual expenses using a fixed withdrawal rate — commonly 4%, based on the "safe withdrawal rate" research from the Trinity Study, which found a portfolio could historically support a 4% initial withdrawal (adjusted for inflation each year) over a 30-year retirement without running out. Dividing your annual expenses by that rate gives the target portfolio size, often called the "25x rule" at a 4% rate (since 1 ÷ 0.04 = 25).
The years-to-FI projection grows your current savings by your expected return each year and adds your annual savings, checking each year whether your balance has reached your FIRE number.
Common questions about FIRE, safe withdrawal rates, and this calculator.
FIRE stands for Financial Independence, Retire Early — the goal of building enough invested assets that ongoing investment returns (rather than a paycheck) can cover your living expenses indefinitely. 'Retire' in this context doesn't necessarily mean stopping work entirely; many people who reach FIRE keep working in some form, but the point is that continuing to work becomes optional rather than financially necessary.
It comes from the Trinity Study (1998) and related research, which tested historical U.S. market returns to find a withdrawal rate that a diversified portfolio could sustain over a 30-year retirement without running out, even in bad market conditions. 4% held up well historically, though it's a rule of thumb, not a mathematical guarantee — some later research suggests slightly lower rates (3-3.5%) are safer for very long retirements (40+ years), which is common in early retirement.
For a traditional ~30-year retirement, historical research suggests it's often enough, but 'often' isn't 'always' — sequence-of-returns risk (a market downturn early in retirement) is the biggest threat to a fixed withdrawal plan. Many FIRE planners build in a buffer by targeting a lower withdrawal rate, keeping some flexibility to reduce spending in a down market, or maintaining a cash reserve to avoid selling investments at a loss.
No — this is a pure investment-portfolio projection based on the expenses and savings you enter. If you expect Social Security, a pension, or other income in later years, your true FIRE number for full retirement may be lower than what's shown here, since those sources would cover part of your expenses. Some people calculate a 'lean FIRE' number for pre-Social-Security years and a different number for after.
That's common and worth revisiting periodically — the calculator's 'annual expenses in retirement' input should reflect your realistic future spending, which may differ from your current spending (no more commuting costs or mortgage, but possibly more travel or healthcare spending). It's worth recalculating your FIRE number every year or two as your actual expenses and investment balance become clearer.
