Coast FIRE Calculator — Find When You Can Stop Contributing
Figure out the portfolio you need today so future compounding does the rest by retirement, even if you stop adding new savings.
Coast FIRE Number
$157,641
Full FIRE Number
$1,200,000
Coast FIRE status
Not yet
Coasting income
$48,000
Timeline
Today
30
2026
Coast FIRE
33.5
2029
Retirement
60
2056
At your current pace, you reach Coast FIRE in about 3.5 years, around September 2029.
Coast FIRE is a financial independence milestone where your current invested portfolio is large enough that compound growth alone will carry it to your full retirement target by a chosen age, even if you never contribute another dollar. Once you reach your Coast FIRE number, you only need to earn enough to cover current living expenses. The concept relies on the historical power of compounding: the S&P 500 has returned approximately 10.3% annually since 1926 (about 7% after inflation), according to NYU Stern data.
How This Calculator Works
The Coast FIRE calculator planning starts with one core question: how much portfolio capital must eventually replace your paycheck? This page answers that question by translating your spending target, investment return assumption, and withdrawal rule into a concrete capital requirement. The calculator uses monthly compounding instead of rough annual shortcuts, which matters because real portfolios grow and contributions land throughout the year. If you are learning the broader FIRE math for the first time, the quickest companion read is our guide on how to calculate your FIRE number, because it explains why spending is the engine behind every retirement target.
Under the hood, the main formula on this page is Coast FIRE number = full FIRE number divided by (1 + real return) raised to the years until retirement. From there, the calculator iterates month by month until your portfolio reaches the required threshold. That approach is more faithful than a back-of-the-envelope estimate because it captures the timing of contributions, compounding, and the nonlinear way returns accelerate once the portfolio gets larger. It also means small changes in monthly savings or return assumptions can shift your timeline materially, which is why the tool updates live as you move sliders and revise spending inputs.
If your full FIRE number is $1.2 million and you have thirty years until retirement with a 7% real return assumption, the Coast FIRE target today is dramatically smaller because compounding does the rest of the heavy lifting. The point is not that one formula can predict the future with perfect accuracy. The point is that a disciplined framework lets you compare scenarios on equal footing. When you change the withdrawal rate from 4% to 3.5%, or reduce planned annual spending by a few thousand dollars, you are not guessing anymore. You are seeing the capital effect directly and understanding which variables deserve your attention first.
Understanding Your Results
The result tells you whether your current portfolio already has enough momentum to reach full FIRE without any new retirement contributions. The most important output is the headline target, but it is not the only one that matters. The years-to-retirement estimate shows how long your current system takes to close the gap. The FI date converts the abstract number into a calendar milestone, which is often more motivating than a raw dollar figure. The inflation-adjusted target reminds you that a million dollars today is not the same as a million dollars twenty years from now, even when you are using real returns for planning.
You should also read the results as a range of plausibility, not as a promise. A projection based on steady real returns can still be disrupted by sequence-of-returns risk, especially early in retirement when withdrawals begin. That is why this site pairs deterministic math with Monte Carlo analysis on the primary FIRE calculator. If the target looks achievable but the success rate is weak, the plan may be mathematically possible while still being too fragile for comfort. In practice, robust plans combine a realistic spending target, a conservative withdrawal rule, and enough flexibility to cut expenses or earn supplemental income if markets disappoint.
A good outcome depends on context. Someone targeting Coast FIRE may gladly accept a leaner lifestyle for more freedom, while someone pursuing a longer or more luxurious retirement may intentionally choose a slower path. The correct read is not whether your timeline is fast or slow in absolute terms. It is whether the timeline fits the life you want and whether the assumptions leave enough margin for inflation, taxes, healthcare, and market volatility. The calculator helps you see those tradeoffs clearly so you can refine the plan rather than react emotionally to a single number.
How to Improve Your FIRE Date
To hit Coast FIRE sooner, focus on front-loading investment contributions during the years when each dollar has the longest runway. Early compounding matters much more here than squeezing out marginal gains later in life. In most cases, the biggest improvement comes from raising your savings rate because that creates a double benefit: you invest more today and, by definition, you need less spending to support tomorrow. The second lever is expenses. Each recurring dollar you remove from planned retirement spending lowers the target portfolio by roughly twenty-five dollars at a 4% withdrawal rate, which is why housing, transportation, and location choices usually matter more than minor budgeting tweaks.
Returns matter, but they should be handled with humility. Chasing higher expected returns by concentrating risk is usually a mistake. A better approach is broad-market index investing, tax efficiency, disciplined rebalancing, and staying invested long enough for compounding to work. Geographic arbitrage can also be powerful if it fits your life. Moving from a high-cost metro to a lower-cost city, lower-tax state, or international destination can reduce both current spending and future retirement needs. The strongest FIRE plans are rarely built by one dramatic move. They come from stacking several sensible decisions that improve flexibility and reduce fragility over time.
Frequently Asked Questions
How much money do I need to retire early with Coast FIRE?
The amount depends on your planned annual spending and withdrawal rate. The standard formula is annual expenses multiplied by 25 (based on a 4% withdrawal rate). For example, $50,000 in annual spending requires roughly $1.25 million. The Trinity Study (1998) found that a 4% initial withdrawal rate, adjusted for inflation, had approximately a 95% success rate over 30-year periods with a balanced stock/bond portfolio. For longer retirements of 40-50 years, many planners recommend targeting 28-33 times annual expenses instead.
Is $1 million enough to retire at 50?
Whether $1 million is enough depends on your annual spending and retirement length. At a 4% withdrawal rate, $1 million supports $40,000 per year. According to the Bureau of Labor Statistics, the average annual expenditure for U.S. households was approximately $72,967 in 2022, so $1 million alone may not cover average spending. However, if you can keep annual expenses below $40,000 through lower housing costs or geographic arbitrage, and especially if you have additional income sources like Social Security starting at 62-67, $1 million can work.
What is the 25x rule for retirement?
The 25x rule states that you need 25 times your planned annual retirement spending saved to retire safely. It is the inverse of the 4% withdrawal rule: if you divide your annual spending by 0.04, you get 25 times that amount. For example, $60,000 in annual spending requires $1.5 million. This rule originates from research by William Bengen (1994) and the Trinity Study (1998), which analyzed historical U.S. market data from 1926 to 1995 and found that a 4% inflation-adjusted withdrawal rate survived most 30-year retirement periods.
How does inflation affect my FIRE number?
Inflation directly increases the portfolio you need. If your FIRE number is $1.25 million today and you are 15 years from retirement, at 3% average annual inflation you would need approximately $1.95 million in nominal terms to maintain the same purchasing power. The Federal Reserve targets 2% inflation, but from 2020 to 2023 annual CPI inflation averaged closer to 5.4% according to BLS data. This calculator shows both real and inflation-adjusted targets so you can plan for purchasing power, not just account balances.
What is a safe withdrawal rate for early retirement?
The traditional 4% rule was tested for 30-year retirements, but early retirees in their 30s or 40s may face 50-60 year retirements. Research by Wade Pfau and others suggests that for retirement horizons longer than 30 years, a 3.25% to 3.5% initial withdrawal rate significantly improves portfolio survival. A 2024 Morningstar study recommended a 3.7% starting withdrawal rate for a 30-year retirement with a 90% success probability. Lower withdrawal rates require larger portfolios but provide a meaningful margin of safety against poor market sequences.
How long will $500,000 last in retirement?
At a 4% withdrawal rate, $500,000 supports $20,000 per year in spending. At a more conservative 3.5% rate, it supports about $17,500 per year. Whether this is sufficient depends heavily on your expenses, location, and supplemental income. Based on historical S&P 500 returns averaging approximately 10.3% annually since 1926 (about 7% after inflation, per NYU Stern data), a $500,000 portfolio with moderate spending has historically lasted 25-35 years in most scenarios. Monte Carlo simulations can show the probability distribution for your specific situation.