🔥 FIRE · Coast FIRE · Find the point where you can stop contributing and let growth do the rest

💡 What is Coast FIRE? It's the point where your invested savings are large enough that — even if you never contribute another dollar — compound growth alone will reach your full retirement target. Once you "coast," you only need to cover current expenses, not save for retirement.

Phase 1: Accumulation

Contribute aggressively until you hit your Coast number. This phase ends the day you coast.

Phase 2: Coasting

Stop investing. Take a lower-stress job, work part time, or anything. Compound growth handles retirement.

Step 1

Your Situation

Current Age

Retirement Age

Current Invested Savings

Annual Contribution

Currently saving per year (before coasting)

Annual Expenses in Retirement

What you'll spend in retirement (today's dollars)

Expected Annual Return

Try:

Results update live as you type

⚠️ Disclaimer & Notice

Results are estimates only. Not guarantees of any financial outcome.

Not financial, legal, tax, or investment advice. We are not a licensed advisor, lender, CPA, or attorney.

Rates, laws, and market conditions change. Investments can go up or down. Past performance does not guarantee future results.

Always consult a licensed professional before making financial decisions.

Terms of Use · Privacy Policy

🏖️ Coast FIRE Summary

Adjust inputs — results update live.

💡 Coast FIRE Explained

The idea: Once you've saved enough, time does the saving for you. Your money just needs 20–35 years to compound to your FIRE target.

After coasting: You don't stop working — you just stop needing to save. A lower-paying job you enjoy is enough. Cover your expenses; retirement is already handled.

More achievable: Coast FIRE often arrives 5–15 years before full FIRE. For many people it's a stepping stone, not a destination.

SWR used: 4% safe withdrawal rate (25× expenses = full FIRE target).

Coast FIRE: The Financial Milestone That Unlocks Freedom While You're Still Working

Coast FIRE is a concept that changes how you think about your career. Once you've invested enough that compound interest alone will grow your portfolio to your retirement number — without any additional contributions — you've "coasted." At that point, you only need to earn enough to cover living expenses. No more race to save every dollar.

The Math Behind Coasting

Let's say you need $1,500,000 at age 65 to retire comfortably. If you're 35 years old with 30 years of growth ahead at 7% real returns, you need today: $1,500,000 ÷ (1.07)^30 = $197,226. If you have $200,000 invested right now at 35, you've hit Coast FIRE. Your money does the heavy lifting from here — you just need to cover your current bills.

The earlier you reach Coast FIRE, the more powerful it becomes. Reaching it at 30 gives 35 years of compounding. At 40, only 25. Each decade of extra compounding roughly doubles your money at 7% (the rule of 72: 72÷7≈10 year doubling time). Starting at 30 vs. 40 means your Coast number requires half as much initial capital.

What Coast FIRE Actually Changes in Your Life

Post-Coast FIRE, your relationship with work fundamentally shifts. You only need to earn enough to live — not to save aggressively. This opens doors to: lower-stress jobs with better work-life balance, part-time work, gig work or consulting, passion projects with modest income, or geographic arbitrage (moving somewhere cheaper). You become less financially desperate, which paradoxically often leads to better career opportunities because you can afford to say no.

Coast FIRE vs. Lean FIRE vs. Fat FIRE

These aren't competing strategies — they're points on a spectrum. Coast FIRE is a milestone: the point where future compounding is secured. Lean FIRE is full retirement on a tight budget (under $40k/year). Fat FIRE is full retirement with comfortable spending (over $100k/year). You might hit Coast FIRE at 35, work a lighter career until 50, then fully retire — capturing elements of all three strategies.

Key Risks to Account For

Investment returns are not guaranteed to average 7%. A prolonged period of lower returns (the 2000s "lost decade" averaged about 2%) could require more time to reach your full retirement number. Account for this by being conservative with return assumptions (5–6% real is safer) and by maintaining flexibility to contribute more if returns disappoint in early years. Also plan for lifestyle inflation — your spending at 55 may be meaningfully higher than at 35.

Coast FIRE Explained: The Mental Model That Changes How You Think About Work

Common Mistakes with Coast FIRE Planning

Using nominal (not inflation-adjusted) return rates. The most critical mistake in Coast FIRE calculations is plugging in a 10% annual return and projecting what that produces by age 65 — without accounting for inflation. A portfolio that grows to $2 million in nominal terms by 2055 may only have the purchasing power of $900,000 in today's dollars if inflation averages 3%. Always use real (inflation-adjusted) return rates in your calculations. A safe planning assumption for a diversified equity portfolio is 6–7% real return. Using 10% nominal means you're dramatically overstating the purchasing power of your future portfolio.

Declaring Coast FIRE before fully stress-testing the number. Once someone believes they've hit Coast FIRE, the temptation is to immediately reduce financial intensity — take a lower-paying job, reduce hours, or stop contributing to retirement accounts. Before making that move, stress-test the projection: what happens if returns average 5% instead of 7%? What if you live to 95 instead of 85? What if healthcare costs inflate at 6% per year? A number that looks solid at 7% returns may fall short at 5% — and unlike traditional FIRE, Coast FIRE gives you less ability to course-correct later.

Forgetting that the Safe Withdrawal Rate (SWR) determines your retirement target. The Coast FIRE number depends entirely on how large a retirement portfolio you'll need. That size is driven by the 4% rule (or your chosen SWR) applied to your annual retirement spending. If you underestimate your annual retirement expenses, your Coast FIRE number is too low — and you'll coast to an insufficient destination. Be honest about your future lifestyle costs, including travel, healthcare, and housing.

Not accounting for Social Security as a future income floor. Most people planning for retirement in their 30s and 40s factor in zero Social Security — either out of pessimism about the program's future or simple omission. But even at a 25% reduction from current promised benefits (the commonly cited worst-case scenario), Social Security can meaningfully reduce how large your portfolio needs to be. Including even a conservative Social Security estimate ($1,000–$1,500/month in today's dollars for average earners) materially lowers your retirement target and therefore your Coast FIRE number.

Confusing Coast FIRE with being financially independent. Coast FIRE means you've saved enough that — if left alone — your portfolio will grow to your retirement number without additional contributions. You still need to cover all your living expenses through earned income for potentially decades. Coast FIRE reduces financial stress and gives you career flexibility; it doesn't eliminate the need to work or earn income.

A Real Example: Alex's Coast FIRE Milestone at 35

Alex is 35 years old and has been aggressively saving for 10 years. He currently has $280,000 invested in low-cost index funds. He plans to retire at 65 and expects to spend $84,000 per year in retirement ($7,000/month). Using the 4% rule, his retirement target is $2.1 million ($84,000 ÷ 0.04). Now the Coast FIRE math: at 7% real annual return over 30 years, $280,000 becomes approximately $2.13 million. Alex has hit his Coast FIRE number. What does this mean practically? He no longer needs to contribute a single dollar to his retirement accounts. His $280,000 will grow on its own to meet his retirement target — purely through compound growth — assuming he doesn't touch it. Alex now has a powerful choice: he can take a job he loves that pays $40,000 less, move to a lower cost-of-living city, work part-time, or start a lower-income business he's passionate about. He still needs to earn enough to cover living expenses, but the retirement savings pressure is completely gone.

When to Use This Calculator

Use this calculator when you want to know how much you need saved — right now — to be able to stop contributing to retirement and still reach your retirement goal. It answers the question: "At what number can I take my foot off the gas?" This is particularly valuable for people who are in high-income but high-stress careers and want to know when they can afford to make a major career change without sacrificing their retirement security.

Run this calculator whenever you receive a significant portfolio milestone — hitting $100K, $250K, $500K — to see how close you are to the Coast FIRE threshold. Each milestone closes the gap, and knowing you're at 70% of your Coast FIRE number often motivates continued aggressive saving to close the remaining 30%.

How to Interpret Your Results

Your Coast FIRE number is the amount you need invested today — before contributions stop — for your portfolio to grow to your retirement target by your retirement age. If you already have this much saved, you've hit Coast FIRE. If you haven't, the calculator tells you how long it will take at your current savings rate to get there.

Years to reach Coast FIRE shows how long until you can stop contributing, given your current balance and monthly contributions. Use this number to find the break-even point: after reaching Coast FIRE, what career or lifestyle changes become available to you? The answer to that question is more motivating than any spreadsheet calculation.

Pro Tips for Coast FIRE Planning

Run both a 7% and a 5% real return scenario. The difference in your Coast FIRE number between these two assumptions is significant. At 7%, you need less saved today because the money works harder. At 5%, you need more saved to arrive at the same destination. Planning with the 5% assumption gives you a conservative buffer — if returns come in at 7%, you'll have more than enough. If returns disappoint at 5%, you're still on track.

Coast FIRE is a one-way door in theory but not in practice. Just because you've hit your Coast FIRE number doesn't mean you must stop contributing. Many people who reach Coast FIRE continue contributing at a lower rate — enough to accelerate their traditional FIRE date rather than coast to age 65. You can always choose to coast slower.

Track your Coast FIRE percentage monthly: (current portfolio value) ÷ (Coast FIRE number) × 100. Going from 40% to 45% to 50% of your target creates a sense of measurable progress. It also makes the number feel less abstract — you're not saving for a vague "retirement," you're buying back career freedom one percentage point at a time.