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Coast FIRE Calculator

When can you stop saving for retirement and let compound growth do the rest? Enter your numbers to find your Coast FIRE target and see when you can start coasting.

How much you plan to spend per year in retirement
Total invested assets today
How much you save and invest each year
Nominal annual return before inflation

Your Coast FIRE Number

$222,281

needed today to coast to $1,000,000 by age 65

45% of coast target$100,000 / $222,281
Coast FIRE Status
Not yet
Coast FIRE Age
38
Full FIRE Number
$1,000,000
Real Return
4.4%

Coast vs. Active Saving

How it works

Methodology

Your Coast FIRE number is the present value of your full FIRE number. It answers: “How much do I need saved right now so that compound growth alone — with zero additional contributions — reaches my retirement target by my target age?”

The formula is straightforward: divide your FIRE number by (1 + real return) raised to the power of years remaining. A $1,000,000 FIRE number with a 4.4% real return and 25 years to go requires about $340,000 today.

The chart shows two paths: the active saving path (contributions + growth) and the coast path (growth only, no contributions after today). The dashed green line shows how the Coast FIRE threshold rises as you approach retirement — because fewer compounding years means a higher starting balance is needed.

All calculations run entirely in your browser. No data is sent to any server.

Common questions

FAQ

What is Coast FIRE?

Coast FIRE is the point at which your existing savings, growing through compound returns alone, will reach your full retirement number by your target retirement age — without any additional contributions. Once you hit Coast FIRE, you only need to earn enough to cover current living expenses. You no longer need to save for retirement.

How is Coast FIRE different from regular FIRE?

Regular FIRE means you have enough saved to retire immediately. Coast FIRE means you have enough saved that you could stop saving and still retire on time, but you still need income to cover today's expenses. Coast FIRE is typically reached much earlier, giving you the freedom to take a lower-paying job, work part-time, or pursue passion projects while your portfolio grows on autopilot.

How is the Coast FIRE number calculated?

Your Coast FIRE number is the present value of your full FIRE number, discounted by your expected real return over the years remaining until retirement. The formula is: Coast FIRE Number = FIRE Number / (1 + real return)^years. For example, if your FIRE number is $1,000,000, your real return is 4.4%, and you have 25 years to retirement, your Coast FIRE number is about $340,000.

What happens after I reach Coast FIRE?

After reaching Coast FIRE, your portfolio is projected to grow to your full FIRE number through compound returns alone. You can stop retirement contributions entirely and focus your income on current expenses. Many Coast FIRE practitioners use this milestone to switch careers, reduce hours, travel, or pursue entrepreneurial projects — any lifestyle where earning enough for today is the only requirement.

Does this calculator account for inflation?

Yes. The calculator uses a real return (nominal return minus inflation) for all projections, so all numbers are in today's purchasing power. Your Coast FIRE number represents what you need in today's dollars, and the growth projection reflects inflation-adjusted returns.

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