At 30, you still have 35 years of compounding before a traditional retirement at 65. With $50,000/yr of retirement spending, a 7% return, 2.5% inflation, and a 4% withdrawal rate, your Coast FIRE number is about $278,000. Cross that line and retirement funds itself — everything you earn afterward is for living, not saving.
Want contributions, a coast-date chart, and adjustable rates? Use the full Coast FIRE calculator.
Assumes retirement at 65, 7% nominal returns, 2.5% inflation, 4% safe withdrawal rate. All figures in today's dollars.
| Retirement spending | Full FIRE number | Coast number at 30 |
|---|---|---|
| $40,000/yr | $1,000,000 | $222,000 |
| $50,000/yr | $1,250,000 | $278,000 |
| $60,000/yr | $1,500,000 | $333,000 |
| $80,000/yr | $2,000,000 | $445,000 |
Each dollar invested at 30 grows to about $4.50 in today's purchasing power by 65. A $278k portfolio quietly becomes $1.25M without another contribution. If you've been maxing a 401(k) with a match since your mid-20s, you may be closer to coasting than you think — and if you're starting late, the gap is still very bridgeable with a few high-savings years.
I have $100k at 30 — am I on track? Against a $278k coast number you're 36% of the way. At $1,500/month invested, most scenarios cross the coast curve within 7–9 years. Model it precisely in the full calculator.
Should I coast or push to full FIRE? Coasting buys flexibility now; pushing buys freedom sooner. Many split the difference — downshift savings rather than stop. Stress-test both paths in the Monte Carlo planner.
What about kids, a house, career breaks? Coast math only covers retirement. Big mid-life expenses need their own funding — the full planner's budget audit handles that.