Coast Retirement · Research
FIRE number calculator
Your FIRE number is the portfolio amount needed to support your annual spending in retirement, commonly estimated by dividing annual spending by a safe withdrawal rate (such as 4%).
What this means
The FIRE number is the finish line for full financial independence — when work is optional because investments can fund spending.
How it works
FIRE Number = Annual retirement spending ÷ Safe withdrawal rate Example: $80,000 ÷ 0.04 = $2,000,000 (same as 25× spending)
Example
Spend $65k/yr, 3.5% SWR → FIRE number ≈ $1.86M. More conservative than 4%.
Assumptions
- Spending is stable in real terms
- Portfolio is diversified
- Withdrawal strategy matches your SWR assumption
Limitations
Ignores taxes, healthcare before Medicare, and account type. Pair with ACA cliff and drawdown planning.
Common mistakes
- Using gross income instead of spending
- Ignoring mortgage payoff timing
- Applying 4% without checking early-retirement research
Related tools
FAQ
What is the 25× rule?
Multiply annual spending by 25 — equivalent to a 4% withdrawal rate.
Is 4% safe for a 40-year retirement?
Many early retirees use 3–3.5% instead; see our safe withdrawal rate guide.
FIRE number vs Coast number?
FIRE number is the target at retirement; Coast number is what you need today to get there without contributing.
Should I include home equity?
Usually only if you plan to downsize or reverse mortgage; otherwise exclude.
Where do I calculate it?
Homepage quick calculator and FIRE types guide.
CoastRetirement.com provides educational calculators and planning models. It does not provide individualized financial, investment, tax, or legal advice. Calculator outputs depend on user-provided assumptions and are not guarantees of future results. Consult a qualified professional before making financial or tax decisions.