Coast FIRE means you have invested enough today that compound interest alone will grow your portfolio to a full retirement target by age 60 or 65 — without contributing another dollar.
Once you hit your "coast number," you still work to cover current living expenses, but the pressure to save aggressively for the future disappears. The result is freedom to downshift careers, reduce hours, accept lower-paying but more meaningful work, or simply stop stressing about retirement.
Unlike Barista FIRE, coast FIRE does not involve withdrawing from the portfolio during the "coasting" phase. The money stays invested and compounds untouched. You work (full-time or part-time) to cover all current expenses until the portfolio reaches maturity.
- How to calculate your coast number
- Canadian-specific factors (CPP, OAS, TFSA, RRSP)
- Why starting early changes everything (and starting late still works)
- How Coast FIRE compares to other FIRE strategies
- The risks that can derail the plan
TLDR: Coast FIRE at a glance
Here is the quick-reference summary.
| Feature | Detail |
|---|---|
| What it is | Save enough now so compounding grows the portfolio to full retirement without further contributions |
| Portfolio withdrawals | None during the coasting phase |
| Work required | Enough to cover current expenses (no savings needed) |
| Formula | Retirement target ÷ (1 + real return)^years = coast number |
| Primary lever | Time (the earlier you start, the lower the number) |
| Canadian considerations | CPP, OAS reduce required portfolio; TFSA withdrawals are tax-free |
How do you calculate your coast number?
The calculation works backward from a future retirement target to determine what you need invested today. The formula is straightforward:
Coast FIRE Number = Target Retirement Portfolio ÷ (1 + annual real return)^years until retirement
The variables include:
- Target retirement portfolio: annual retirement expenses × 25 (based on 4% withdrawal rate)
- Annual real return: expected investment growth minus inflation (typically 5%-7%)
- Years until retirement: your planned retirement age minus your current age
So, for example, a 30-year-old who wants to retire at 60 on $40,000/year:
- Years: 30
- Real return: 6%
- Target portfolio: $40,000 × 25 = $1,000,000
- Coast number: $1,000,000 ÷ (1.06)^30 = ~$174,000
If this person has $174,000 invested at age 30 and never contributes again, the portfolio should grow to $1 million by age 60 (assuming 6% real returns). Every dollar earned after hitting this number can go entirely toward living, experiences, and building an emergency fund.
Why does starting age change everything?
Compounding is exponential — gains in later years are dramatically larger than in early years. The coast number at 25 is far lower than at 40 because money has more time to double (and double again).
| Current age | Coast number (retire at 60, $40k/year, 6% real) |
|---|---|
| 25 | ~$130,000 |
| 30 | ~$174,000 |
| 35 | ~$233,000 |
| 40 | ~$312,000 |
| 45 | ~$418,000 |
The difference between starting at 25 and starting at 40 is $182,000 — entirely because of lost compounding time.
For anyone using dollar cost averaging to build their portfolio, the message is clear: the earlier you reach your coast number, the less total money you actually need to invest.
What are the Canadian-specific considerations?
Canadian Coast FIRE planning includes government benefits and tax-advantaged accounts that change the math.
CPP and OAS
Canada Pension Plan and Old Age Security act as a built-in "pension" that reduces the portfolio's withdrawal burden in retirement. A typical retiree might receive ~$700/month from CPP and ~$650/month from OAS — roughly $16,200/year. Including government benefits in your calculation can lower the required retirement portfolio (and therefore the coast number) by 20%+ for moderate spenders.
Account types
Withdrawal tax treatment varies by account:
- For TFSA, withdrawals are entirely tax-free (the most efficient Coast FIRE "bucket" for Canadian residents)
- For RRSP/RRIF, withdrawals are taxed as income (meaning you need a higher gross amount to meet net spending targets)
- For non-registered accounts, it is subject to capital gains and dividend taxes
Inflation assumption
Many Canadian calculators default to the Bank of Canada's 2% target inflation (rather than the 3% commonly used in U.S. models), which slightly lowers the coast number.
Using the more conservative 3% adds a safety margin. You have to know your TFSA and RRSP contribution limits to maximize the tax-free compounding window.
What can go wrong?
Coast FIRE's greatest strength (set it and forget it) is also its greatest vulnerability. The plan depends on decades of uninterrupted compounding — and life rarely cooperates for 30 straight years.
- Higher-than-expected inflation erodes the purchasing power of the future portfolio
- Prolonged market underperformance (a "lost decade" delays compounding significantly)
- Lifestyle inflation after hitting the coast number (spending rises because saving pressure is gone)
- Career disruptions that eliminate income for current expenses — forcing portfolio withdrawals
- Dipping into the coast portfolio early (for emergencies, job loss, or healthcare) resets the compounding clock
It can be mitigated by using conservative return assumptions (5%-6% real instead of 7%+), building a separate emergency fund outside the coast portfolio, and periodically recalculating your number as life circumstances change. Coast FIRE is not "set and forget forever" — it is "set, monitor, and adjust."
Frequently asked questions
Here are some commonly asked questions about Coast FIRE:
What is the difference between Coast FIRE and Barista FIRE?
Coast FIRE means you have already invested enough for retirement, assuming the money stays invested and grows until your target retirement age. During the coast phase, you still work enough to pay current living expenses, but you no longer need to save aggressively for retirement. Barista FIRE is different because it usually involves withdrawing some money from the portfolio while also working part-time to cover the gap. Coast FIRE protects compounding by leaving the portfolio untouched. Barista FIRE gives more immediate lifestyle freedom, but it introduces withdrawal risk earlier and depends more heavily on market timing, health benefits, and part-time income.
Can I reach Coast FIRE in my 40s?
Yes, but reaching Coast FIRE in your 40s usually requires a larger portfolio because there is less time for compounding to do the work. A 30-year-old has three decades for investments to grow before age 60, while a 45-year-old may have only 15 years. That shorter runway means the coast number rises quickly. The idea still works, especially for people with strong savings, home equity, pensions, or a lower retirement spending target. The practical approach is to use conservative return assumptions, include only reliable income sources, and recalculate each year rather than relying on a single estimate.
Should I include CPP and OAS in my Coast FIRE calculation?
You can include CPP and OAS, but it is wise to run the calculation both with and without them. CPP is linked to your contribution history, so your expected benefit may be more predictable if you check your official estimate through your My Service Canada Account. OAS depends on residency, age, income, and future rules, so many planners discount it or include only part of it. In 2026, official figures show meaningful support from both programs, but they do not replace personal savings for everyone. Treat government benefits as one layer of retirement income, not the whole plan.
What if the market underperforms for a decade?
A weak market can delay Coast FIRE because the plan depends on long-term compounding. If returns are lower than expected during the coast phase, the portfolio may not reach the target by the planned retirement age. The best defense is to use modest real return assumptions, such as 4% to 5%, rather than assuming strong growth every year. You can also build a margin of safety by slightly overshooting your coast number, continuing small contributions, or staying flexible on retirement age. Coast FIRE should be reviewed regularly. It is a planning checkpoint, not a promise that markets will cooperate.
How do I calculate my Coast FIRE number?
Start with your expected annual retirement spending, subtract reliable retirement income such as CPP, OAS, or a pension, then multiply the remaining amount by your chosen retirement multiple. Many people use 25 times annual expenses as a rough version of the 4% rule. Then discount that future target back to today using your expected real return and years until retirement. For example, a $1,000,000 target in 30 years discounted at a 6% real return requires about $174,000 today. The formula is helpful, but the result is only as good as your assumptions about spending, taxes, inflation, and returns.
Is the 4% rule safe for Coast FIRE?
The 4% rule is a useful starting point, not a guarantee. It comes from research on retirement withdrawal rates, where the goal was to test whether a portfolio could survive a long retirement under historical market conditions. Coast FIRE adds another layer because you are also projecting portfolio growth for many years before withdrawals begin. A 25-times-expenses target can be reasonable, but it may be too low for early retirees, cautious investors, high-fee portfolios, or people with little spending flexibility. Many Coast FIRE plans use a lower withdrawal rate, such as 3.5%, to create more room for error.
Which Canadian accounts are best for Coast FIRE?
For many Canadians, a TFSA is the cleanest Coast FIRE account because investment growth and withdrawals are tax-free. An RRSP can also be powerful, especially if you are in a higher tax bracket today and expect a lower tax rate in retirement. Non-registered accounts add flexibility once registered accounts are full, but taxes on dividends, interest, and capital gains must be included in planning. The best order depends on income, employer pensions, debt, family benefits, and expected retirement tax brackets. A strong Coast FIRE plan usually uses all available tax shelters before relying heavily on taxable investing.
Should I keep investing after I hit my Coast FIRE number?
You do not have to, but continuing even small contributions can make the plan safer. Coast FIRE means you could stop saving for retirement if assumptions hold. It does not mean saving more is useless. Extra contributions can offset lower returns, higher inflation, future tax changes, or a more expensive lifestyle. They can also move your retirement date earlier or give you more choices later. Some people stop all retirement contributions and use the income for their current life. Others keep contributing lightly as a safety margin. The better choice depends on how much certainty you want and what trade-offs matter now.
Can I pursue Coast FIRE while paying off debt?
Yes, but the type of debt matters. High-interest debt, such as credit card debt, should usually be paid off before serious Coast FIRE investing because the guaranteed cost is often higher than any reasonable expected return. Low-interest debt, such as a mortgage or some student loans, can be managed alongside investing if payments are affordable and the household has an emergency fund. Coast FIRE works best when the portfolio can stay untouched for decades. If debt payments are likely to force withdrawals later, the plan becomes fragile. A balanced path pays down risky debt while steadily building long-term investments.
How does inflation affect Coast FIRE?
Inflation matters because Coast FIRE calculations are about future purchasing power, not just future dollars. If your target is $40,000 per year in today's money, you need the future portfolio to support the inflation-adjusted version of that lifestyle. One way to handle this is to use a real return, meaning investment return after inflation. For example, if investments earn 7% and inflation averages 2%, the real return is roughly 5%. Using real returns keeps the calculation in today's dollars, making it easier to understand. Higher inflation lowers purchasing power and can raise the amount needed to coast safely.
