Coast FIRE is the point where you’ve invested enough that, even if you never add another euro, compounding alone will grow your portfolio to your retirement target. After that, your job only needs to cover today’s living costs, not your future savings. This calculator works out the number you need invested today to coast to retirement.
Coast FIRE Calculator
What Coast FIRE Means
Reaching Coast FIRE doesn’t mean you can retire now. It means you can stop saving for retirement. Your existing investments are already on track to hit your target by your chosen retirement age, so any further income just covers your current lifestyle. For a lot of people that’s the most liberating milestone on the path, well before full financial independence: it takes the pressure off, lets you switch to lower-paid work you enjoy, or simply spend what you earn.
How to Use This Calculator
Enter your current age, the age you want to retire, and the annual spending you’ll need then. Set your expected return and withdrawal rate, add the European tax adjustment if your withdrawals will be taxed, and enter what you’ve invested so far. The calculator shows the Coast FIRE number you’d need today and whether your current portfolio has reached it.
The Math
First it works out your retirement target, the full FIRE number, as annual expenses divided by your withdrawal rate, grossed up for tax. Then it discounts that target back to today using your expected return over the years until retirement:
Coast number = Target ÷ (1 + r)years
The longer you have until retirement, the smaller the amount you need today, because compounding has more time to work. A 30-year-old needs far less invested to coast than a 50-year-old aiming for the same target.
A European Note on Tax
As with the FIRE calculator, the tax field matters. If your gains are taxed on withdrawal, your real retirement target is higher than a US calculator would tell you, which in turn raises the amount you need invested today to coast. Enter your effective rate for a realistic figure.
What This Calculator Doesn’t Model
- Inflation, so think of the target in today’s money and use a real return if you prefer.
- Any contributions after today; the whole point is to assume you stop.
- Sequence-of-returns risk and market variability around the average.
Next Steps
If you haven’t reached Coast FIRE yet, the compound interest calculator shows how regular contributions close the gap, and the FIRE calculator gives you the full timeline. To put any of it into practice, start with my guide to investing for European residents.
