Coast FIRE Calculator

The Coast FIRE formula

Coast number = (25 × annual spending) ÷ (1 + real return)^{years until retirement}

A $50,000/year retirement needs $1.25M by the 4% rule. At age 32 with 33 years of 7% real growth ahead, today's requirement is only about $134,000 — because $134,000 × 1.07³³ ≈ $1.25M. Reach that, and retirement is funded even if you never save another dollar.

What Coast FIRE actually buys you

Not early retirement — early freedom of choice. Once past your Coast number, your job only needs to cover current living costs. That unlocks: switching to lower-paid meaningful work, part-time schedules, risky startups, long sabbaticals — all without touching the retirement machine that is already running. It is the cheapest form of financial independence because compounding does the heavy lifting.

The honest caveats

• The math assumes decades of ~7% real returns — historically reasonable, never guaranteed. Many coasters keep contributing a token amount as buffer.
• Your spending target decades out is a guess; revisit it every few years.
• Health insurance before Medicare age remains the hard American problem for anyone downshifting early.