Coast FIRE
When you can stop saving and still retire on timeCoast FIRE is the point where what you've already invested will grow into your full FIRE number by retirement age, without another cent added. From then on you only need to earn what you spend. You can take a job you like more, work fewer hours, or take a long break, and your retirement is still on track.
The formula
Take your FIRE number and shrink it by the growth you expect between now and retirement. Use a return after inflation so everything stays in today's money.
Coast number = FIRE number ÷ (1 + real return) ^ years to retirement €750,000 ÷ 1.049 ^ 30 ≈ €178,000
That's someone aged 35 who wants to retire at 65 on €30,000 a year, with 7% returns and 2% inflation (about 4.9% after inflation). With €178,000 invested today, they could stop saving and still reach €750,000 at 65.
Starting early does most of the work
The same €750,000 at 65 needs very different amounts depending on when you start coasting:
| Coasting from age | Years of growth | Coast number |
|---|---|---|
| 25 | 40 | €111,000 |
| 35 | 30 | €178,000 |
| 45 | 20 | €288,000 |
| 55 | 10 | €465,000 |
How much the return matters
Thirty years of compounding magnifies small differences in the return you assume. Here is the same 35-year-old's coast number at three real returns, and the age they could stop saving if they start from €50,000 and add €1,000 a month:
| Real return | Coast number | Stop saving at |
|---|---|---|
| 4% | €231,000 | 58 |
| 4.9% | €178,000 | 50 |
| 6% | €131,000 | 43 |
If returns come in a little lower than planned, you find out late, when there's less time to catch up. Check once a year whether you're still on track, and plan with a return you'd be comfortable falling short of.
Coast FIRE only covers retirement. Losing your job still means finding another one, or eating into the portfolio you're counting on to grow.
Coast FIRE and Barista FIRE
Both mean working less before you're fully independent, and people mix them up. With Coast FIRE you stop adding money, but you don't touch the portfolio until you retire. With Barista FIRE you start living off the portfolio straight away, and a part-time job covers the rest.
New to all this? Start with What is FIRE.