Coast FIRE Calculator
The point where your investments will reach your full retirement target — with zero additional contributions from you.
Your Coast FIRE Number
$310,286
$1,250,000
Full FIRE Target
Status
Keep going — you've got ground to cover
How it works
The math is straightforward. Your Coast FIRE number is the amount you need invested today so that it grows to your full retirement target by your planned retirement age — with no further contributions.
Coast FIRE Number = Full FIRE Target ÷ (1 + r)years-to-retirement
Example: $1,250,000 ÷ 1.0735 = $310,286. At that amount, compound growth alone carries you the rest of the way.
Social Security is not included
This calculator uses your full annual expenses. If you expect Social Security income, your actual portfolio target may be lower. Check your estimate at ssa.gov/my-account.
For educational purposes only. Assumes constant returns, no Social Security income. Not financial advice.
What Is Coast FIRE?
Coast FIRE is a milestone in the financial independence movement where you have saved enough that compound growth alone — with zero additional contributions — will carry you to your full retirement target by traditional retirement age. It is the point at which you could stop saving entirely and still retire on schedule.
The appeal is psychological as much as financial. Once you hit your Coast number, you are no longer trading time for money at the same intensity. You have more freedom to choose lower-paying work that you find meaningful, to reduce your hours, or to take a sabbatical without derailing your retirement plan.
How Is Coast FIRE Different From Full FIRE?
Full FIRE requires you to accumulate 25× your annual expenses (the 4% rule). For someone spending $60,000 a year, that is $1.5 million. Coast FIRE requires far less — typically 40–70% of your full FIRE number — because you are relying on a shorter runway of compound growth rather than a fully-funded portfolio that must sustain decades of withdrawals.
The trade-off is that you still need earned income to cover your current living expenses until traditional retirement. You have crossed the line where your money works for you instead of the other way around, but you have not yet reached full independence.
Who Coast FIRE Is Best For
Coast FIRE is particularly powerful for people in their 20s and 30s who discovered investing early. A 30-year-old who started investing at 22 with a 7% real return has 30–35 years of compound growth ahead — meaning their required Coast number is surprisingly small relative to their final target. For them, the math is generous.
It is less useful as a terminal strategy for people who hate their jobs and want to quit immediately. If you want to stop working in the next five years, you need full FIRE, not Coast FIRE. But if you want to work on your own terms in your 40s and 50s, Coast FIRE is one of the most practical milestones you can target.
The 4% Rule and Coast FIRE
The Coast FIRE formula uses the 4% rule as its foundation: your full FIRE target equals your annual expenses × 25. The calculator discounts that number back through your expected return rate for your remaining working years to find the amount you need invested today. The assumption is that your portfolio will grow at roughly 7% annually before inflation, or about 5% in real terms after inflation.
Those return assumptions matter. A 1% difference in your expected return rate can shift your Coast number by 15–20%. If you are uncertain whether your assumptions are realistic, use a conservative rate (5–6%) to avoid the painful experience of falling short of your Coast milestone.