Coast FIRE Calculator

Calculate how much you need invested today to coast to financial independence

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This is your investment's overall (nominal) rate of return before adjusting for inflation. Historically, the S&P 500 has returned on average 10% annually from its inception in 1926 to 2018.

7%

This is the average annual rate of inflation that you expect to experience in the future. Historically, the US economy has experienced an annual average inflation rate of 3%. This value is used to normalize the calculator to be in 2020 dollars.

3%

Safe withdrawal rate (SWR) is the percentage of your net worth that you withdraw each year in retirement. 4% is widely considered as the recommended SWR for retirement planning.

4%

Coast FIRE Number at Current Age

$175,723

Years from Coast FIRE

18 years

The Math Behind the Calculator

Coast FIRE is the amount you need invested today to reach your FIRE number by retirement age, without making additional contributions.

FIRE Number = Annual Spending ÷ Safe Withdrawal Rate
Coast FIRE Number = FIRE Number ÷ (1 + Real Growth Rate)^Years to Retirement
Real Growth Rate = (1 + Investment Rate) ÷ (1 + Inflation Rate) - 1

The 4% withdrawal rate is based on the Trinity Study, which found this rate to have a 100% success rate over a 30-year retirement horizon with a balanced portfolio.

Investment Growth Projection

Year Age Beginning Balance Annual Contributions Investment Growth Ending Balance

Coast FIRE Calculator

The Coast FIRE Calculator is a financial planning tool designed to help individuals determine how much money they need invested today to “coast” into retirement without making any additional contributions. The term Coast FIRE (Financial Independence, Retire Early) refers to reaching a point where your current investments will grow enough—on their own—to fund your retirement by the time you reach your retirement age.

Rather than aggressively saving for decades, Coast FIRE allows you to reduce or even stop contributions once you’ve hit your Coast FIRE number. It’s ideal for those who want financial flexibility, a better work-life balance, or the option to switch to passion projects or part-time work long before traditional retirement age.

Features of the Coast FIRE Calculator

  • Personalized Inputs: Set your current age, retirement age, annual spending in retirement, current assets, monthly contributions, investment growth rate, inflation rate, and withdrawal rate.

  • Real-Time Calculations: Instantly calculates your Coast FIRE Number, how many years away you are from it, and your retirement readiness.

  • Detailed Growth Table: View year-by-year projections of your investments, including contributions, growth, and ending balances.

  • Export Functionality: Easily export your financial projections as a CSV file for personal records or use with financial advisors.

  • Educational Notes: Includes contextual definitions and references (e.g., S&P 500 average return, inflation trends, Trinity Study) to help you understand the math behind the calculator.

  • Copy Buttons: One-click copy functionality for key metrics like Coast FIRE Number and Years from Coast FIRE.

Advantages

  • Early Clarity: Understand how close you are to financial freedom without waiting until your 60s to plan.

  • Peace of Mind: Once you hit your Coast FIRE number, future financial contributions become optional.

  • Flexible Lifestyle: Encourages career flexibility, sabbaticals, or lower-stress work, while investments quietly grow.

  • Informed Decisions: Use real market assumptions to estimate retirement readiness accurately.

  • Optimized Saving: Avoid over-saving or under-saving by identifying the exact amount required today.

Use Cases

  • Mid-career professionals planning to reduce working hours or switch to a passion career.

  • Young investors curious about how early contributions can lead to long-term financial independence.

  • FIRE movement enthusiasts wanting to hit financial freedom milestones earlier in life.

  • Financial advisors helping clients understand whether they can afford to slow down.

  • Dual-income families exploring options for one partner to take a career break.

  • Freelancers and solopreneurs seeking part-time income models after hitting Coast FIRE.

Importance of Coast FIRE

Unlike traditional FIRE, which requires a large sum to retire immediately, Coast FIRE is about time and compounding. By identifying your Coast FIRE number early, you empower yourself to:

  • Reclaim your time without sacrificing future security.

  • Prioritize well-being and passion without guilt.

  • Navigate life transitions (parenthood, travel, education) with confidence.

  • Live with purpose, knowing your retirement is already taken care of.

Why Coast FIRE Is Gaining Popularity

  • As the FIRE movement matures, Coast FIRE has become a realistic middle path for people who want financial independence without extreme frugality or quitting work entirely.

    Unlike traditional FIRE that often demands saving 50–70% of your income, Coast FIRE emphasizes early, aggressive investing followed by reduced savings pressure later in life. It’s especially popular among:

    • Millennials and Gen Z professionals

    • Creatives and entrepreneurs

    • Families who want a slower pace of life

    • Anyone disillusioned with hustle culture

Common Misconceptions

MisconceptionReality
You need to retire completelyCoast FIRE allows you to continue working, but optionally
You must stop investing after hitting Coast FIRENo—you can continue for extra cushion
It’s only for high earnersAnyone can achieve Coast FIRE with early and consistent saving
Coast FIRE equals financial independence nowNot yet—you’ll be financially independent at retirement age
You need complex math to figure it outThe calculator does all the heavy lifting for you

FAQs About Coast Fire Calculator

Coast FIRE is a financial independence strategy where you invest enough early so that your retirement is fully funded without needing to make additional contributions after a certain point.

It calculates the amount you need invested today (Coast FIRE number) to reach your target retirement goal using compound growth, even if you stop contributing.

You need to enter your current age, retirement age, expected annual retirement spending, current investments, monthly contributions, expected investment return, inflation rate, and safe withdrawal rate.

It’s the percentage of your retirement portfolio you can safely withdraw each year without running out of money—typically assumed to be 4%.

Not necessarily. Coast FIRE means you can stop, but you may continue contributing to build more wealth or for peace of mind.

It uses widely accepted financial formulas and assumptions but should be treated as a projection, not a guarantee. Always re-evaluate yearly.

You can recalculate using the updated retirement age to reflect new Coast FIRE and FIRE numbers.

Any investments with expected growth—stocks, ETFs, mutual funds, etc. Ideally long-term, diversified portfolios.

Once reached, you gain the freedom to stop saving aggressively, pursue lower-paying passion work, or enjoy more work-life balance.

Not better—just different. Coast FIRE is ideal for those who want more flexibility without retiring early.