Coast FIRE calculator

The point where your invested assets, left completely alone, would compound to your full FIRE number by your target retirement age. Mathematically: FIRE number ÷ (1 + real return)^{years remaining}. On the default scenario — $55,000/yr spending, retiring at 65, 5% real — a 32-year-old needs $274,825 today to coast. Past that line, retirement at 65 is mathematically funded whether you ever save again or not.

Nothing — and everything. The portfolio doesn’t care; it compounds either way. What changes is your relationship with income: every dollar you earn after coast only needs to cover current spending, not the future too. That unlocks the downshifts people actually want — part-time, a passion-wage career, one income instead of two, a sabbatical — decades before full retirement. It’s the FIRE variant for people who like their work but want it optional-ish.

Discounting. Your FIRE number shrinks by the real return for every year between now and retirement: at 5% real, money doubles roughly every 14 years, so a 30-year-old retiring at 65 needs only about 18% of their FIRE number banked to coast (1.05³⁵ ≈ 5.5×). The corollary cuts both ways — coast numbers balloon as the runway shortens, which is why this is overwhelmingly a young person’s milestone and a poor late-career target.

It carries real risks the clean math hides. The projection assumes your spending target and the real return both hold for decades — a bad first decade, lifestyle creep, or a 3% real world instead of 5% pushes the funded date back, and a coaster by definition isn’t adding new money to repair it. Sensible practice: coast on a conservative return assumption (5%, not 7%), keep some contribution flowing, and re-run the number yearly. Treat coast as a milestone that buys flexibility, not a contract that guarantees a date.

Same answer as any long-horizon Canadian portfolio, with extra weight on costs since no new contributions will paper over drag: a diversified all-in-one ETF at ~0.2%, inside the TFSA and RRSP first, at a $0 broker. A 2% mutual-fund MER quietly converts a coast plan into a shortfall — the fee calculator shows how brutally.

The FIRE calculator answers “when can I stop working entirely?” and shows your coast number against a fixed age-65 anchor. This page makes the coast question first-class: an adjustable target age (coast to 55 if that’s the plan), the gap to your coast line, and how long your current savings pace takes to cross it. Same math, different question. The strategy context is in the FIRE in Canada guide.