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Coast FIRE Calculator

At what point can you stop saving and let compound growth carry you to retirement? Find your Coast FIRE number, discover when you will hit it, or plan your coast lifestyle. Works with any currency.

All amounts displayed in selected currency
$
How much you want at retirement (e.g. 25x annual expenses)
The age you plan to retire
Your age today
%
Average annual investment return (7% is a common long-term estimate)
Estimates only. No taxes applied. Consult a financial adviser for personalised guidance.

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How to Use This Calculator

Tab "Coast Number"

Enter your target retirement amount (e.g. 25x annual expenses), retirement age, current age, and expected annual return. The result shows your Coast FIRE number — the savings threshold where compound growth alone carries you to your goal.

Tab "When Can I Coast"

Enter your current savings, monthly contribution, expected return, retirement age, and target amount. The calculator simulates month by month to find the exact age and date when your portfolio crosses the coast number.

Tab "Coast Lifestyle"

Enter your current income, the minimum income you need while coasting, and your savings details. The result shows whether you can already coast, how much income you can give up, and what your savings will grow to by retirement with zero new contributions.

The Formula

Coast FIRE Number:
Coast FIRE Number = Target Retirement Amount / (1 + r)years_to_retirement

Where:
r = expected annual return (as a decimal, e.g. 0.07 for 7%)
years_to_retirement = retirement age − current age

Interpretation:
This is the present value of your retirement target. Once your savings reach this number, compound growth alone will do the rest.

All calculations use standard compound interest math. No country-specific tax rates or inflation adjustments are applied. For real (inflation-adjusted) planning, use a real return rate (e.g. 4–5% instead of 7%).

Worked Examples

Example 1 — Age 30, target $1.5M at 65, 7% return

A 30-year-old wants $1.5 million by age 65 and expects a 7% average annual return on investments.

Target at retirement$1,500,000
Retirement age65
Current age30
Years to retirement35
Growth factor(1.07)35 = 10.677
Coast FIRE number$1,500,000 / 10.677 = $140,482

Once this person saves $140K, they can stop contributing entirely. At 7% annual growth, $140K grows to $1.5M over 35 years.

Example 2 — Age 28, $45K saved, $2,000/mo, 8% return

A 28-year-old has $45,000 in savings, contributes $2,000 per month, and earns 8% annually. Target: $1.5M at 65.

Current savings$45,000
Monthly contribution$2,000
Expected return8%
Coast number at age 33$1,500,000 / (1.08)32 ≈ $123K
Savings at age 33≈ $123K+ (crosses coast number)
ResultCan coast at approximately age 33

After about 5 years of saving, this person hits their coast number. They can then stop saving for retirement and let compound growth do the work for 32 more years.

Example 3 — Earns $95K, coasting on $55K/yr

A 33-year-old earns $95,000/yr and has $197,000 saved. Their coast number is about $197K (target $1.5M at 65, 7% return). They can switch to a $55K/yr role.

Current income$95,000/yr
Coast income needed$55,000/yr
Income reduction$40,000/yr
Current savings$197,000
Coast number$1,500,000 / (1.07)32 ≈ $172K
StatusAlready past coast number — ready to coast

This person can switch to a part-time role, a passion project, or a lower-stress $55K/yr job. Their $197K grows to $1.5M+ by 65 without any new contributions. The $40K/yr income drop is the price of freedom.

Understanding Coast FIRE

What Is Coast FIRE?

Coast FIRE (Financial Independence, Retire Early) is the point where you have saved enough that compound growth alone will grow your portfolio to your retirement target — without any further contributions. After reaching Coast FIRE, you only need to earn enough to cover current living expenses. You are "coasting" to retirement.

Coast FIRE vs. Traditional FIRE

Traditional FIRE means accumulating 25x your annual expenses so you can stop working entirely. Coast FIRE is a milestone on that journey: you have enough invested that time and compounding will do the rest. You still work, but you no longer need to save aggressively. This makes it achievable years or even decades before full FIRE.

The Power of Compound Growth

Coast FIRE works because of exponential growth. At 7% annual returns, money doubles roughly every 10 years. A 30-year-old with $140K can reach $1.5M by 65 without adding another dollar. The earlier you start, the smaller your coast number — because you have more years for compounding to work.

Limitations

Coast FIRE calculations assume: (1) steady average returns, when in reality markets are volatile, (2) no major withdrawals before retirement, (3) your target amount and retirement age remain fixed. Sequence-of-returns risk, inflation, and lifestyle changes can all affect the outcome. Use this as a planning tool, not a guarantee.

Frequently Asked Questions

Your Coast FIRE number is the amount of savings you need today so that compound growth alone — with zero additional contributions — will grow your portfolio to your retirement target. It is calculated as: Target / (1 + return)^years. For example, $1.5M target at 7% return with 35 years to go means a coast number of about $140K.
Regular FIRE means you have accumulated enough to stop working entirely (typically 25x annual expenses). Coast FIRE is reached much earlier — you have enough invested that compounding will get you to your FIRE number, but you still need to earn enough to cover current expenses. You stop saving, not stop working.
A common assumption is 7% for nominal stock market returns (S&P 500 long-term average is about 10%, minus 3% inflation). For conservative planning, use 5-6%. For aggressive planning, 8-9%. The choice depends on your portfolio allocation and risk tolerance. Using a lower rate gives a higher (safer) coast number.
Technically yes — Coast FIRE only concerns your invested savings. However, high-interest debt (credit cards, personal loans) may grow faster than your investments. Pay off high-interest debt first. Low-interest debt (mortgage, student loans) can coexist with a coast strategy, but factor debt payments into the income you need while coasting.
No. This is a universal pre-tax calculator using nominal returns. To account for inflation, use a real return rate (subtract expected inflation — e.g., use 4% instead of 7%). Tax treatment varies by country and account type (401k, ISA, etc.). For country-specific retirement calculators, see the related links below.

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