How FI Runway works

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How FI Runway works

A free FIRE calculator: freedom number, years to financial independence, projected path, and FI styles - with clear assumptions and limits.

Three steps

  1. 1

    Enter your numbers

    Invested today, monthly investing, freedom spending, age, and return assumptions - in the sidebar.

  2. 2

    See your timeline

    Freedom number, years to FI, projected path, and progress for your selected goal style.

  3. 3

    Compare & adjust

    Switch FI styles, read the levers, and see what moves your date.

Methodology

How we calculate your path

Freedom number

Annual freedom spending ÷ withdrawal rate (you set both in the sidebar). Example: $49,200/year at 4% → about $1.23M invested target.

Years to FI

We compound invested balances at your expected return and add monthly contributions until invested assets first reach your active goal target (Standard, Lean, Coast, or another style).

Coast FI & other styles

Coast FI uses a present-value target: enough invested today so growth alone reaches full FI by your target age. Lean, Barista, and Fat FI adjust spending or income assumptions - see the FIRE numbers grid on the calculator.

Net worth vs FI progress

The chart shows projected invested assets over time. The green marker is when that line crosses your target.

What we do not model

  • Tax, benefits, or country-specific rules
  • Sequence-of-returns risk in detail
  • Dynamic spending in retirement
  • Personalized advice - this is a planning sketch, not a forecast

Related guides

FAQ

Frequently asked questions

The invested portfolio size you need so work becomes optional on paper: annual freedom spending divided by your withdrawal rate (often 4%). It is a planning target, not a guarantee.