Coast FIRE: How to Stop Saving Early and Still Retire Comfortably
Quick Answer: Coast FIRE is the amount you need invested such that compound growth alone reaches your retirement target by 65 without additional savings. At age 32 with $160,000 invested earning 7% annually, you’ll have ~$1.5 million by 65. Once you hit your coast number, you only need to earn enough to cover current expenses, not aggressively save.
There’s a version of FIRE most people don’t talk about — one that doesn’t require an extreme savings rate, a bare-bones lifestyle, or a rigid timeline. One where, at some point, you stop contributing to retirement entirely and let compound interest do the rest.
It’s called Coast FIRE, and once you understand the math, it might change how you think about your financial life.
What Is Coast FIRE?
Coast FIRE is the milestone at which you have saved enough in your investment accounts that, even if you never contribute another dollar, your existing balance will compound to your retirement target by your traditional retirement age.
After hitting Coast FIRE, you can technically stop investing for retirement. You can “coast” — meaning you only need to earn enough to cover your current living expenses, not aggressively save on top of them. The market does the saving for you.
The name comes from the image of a bicycle: you’ve pedaled hard up the hill, built up enough speed, and now you can take your feet off the pedals and coast to the bottom. The momentum carries you.
The Math Behind Coast FIRE
To understand Coast FIRE, you need to internalize two numbers:
Your retirement target — the lump sum you need to fund retirement at your desired spending level. A common calculation: multiply your desired annual retirement spending by 25 (the 4% rule inverse). If you want to spend $60,000/year in retirement, your target is $1,500,000. (Learn more about calculating your FIRE number.)
Your current invested balance — what you have in all retirement and investment accounts today.
The question Coast FIRE answers: If I invest my current balance at a 7% real return (10% nominal minus 3% inflation), how large will it be in 30 years? In 25 years? In 20?
The formula is: Future Value = Present Value × (1 + r)^n
Where r = 7% (real return assumption) and n = years to target retirement age.
Example:
Maya is 32 years old with $120,000 in invested assets (401k, IRA, brokerage combined). She wants to retire at 65 with $1,500,000 (in today’s dollars).
$120,000 × (1.07)^33 = $120,000 × 9.33 = $1,119,600
Not quite there. She needs a bit more before she hits Coast FIRE.
At $160,000 invested: $160,000 × 9.33 = $1,493,000 ≈ $1,500,000 ✓
Maya’s Coast FIRE number is approximately $160,000. Once she hits that mark, she never needs to contribute to retirement accounts again. She can earn just enough to cover her expenses and let compound interest handle the rest.
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Coast FIRE Numbers by Age
Here’s what you’d need invested today for $1,500,000 at age 65, assuming a 7% real annual return:
| Current Age | Years to 65 | Coast FIRE Target | Growth Multiple |
|---|---|---|---|
| 25 | 40 | $73,000 | 20.7x |
| 30 | 35 | $103,000 | 14.6x |
| 32 | 33 | $120,000 | 12.5x |
| 35 | 30 | $146,000 | 10.3x |
| 40 | 25 | $205,000 | 7.3x |
| 45 | 20 | $289,000 | 5.2x |
| 50 | 15 | $408,000 | 3.7x |
The younger you reach your Coast FIRE number, the less you needed to save — because time does the compounding work.
Note: Adjust the retirement target for your actual spending needs. $1,500,000 at 4% withdrawal = $60,000/year in retirement spending. Scale accordingly.
Coast FIRE Calculators
If you prefer visual tools to running the math manually, these free calculators automate the Coast FIRE calculation:
- ProjectionLab — Detailed scenario modeling with Coast FIRE milestone tracking
- cFIREsim — Historical Monte Carlo simulations for Coast FIRE dates
- FIRECalc — Simple Coast FIRE target calculator with sensitivity analysis
All three let you input your current age, invested balance, desired retirement spending, and target retirement age. They’ll tell you your exact Coast FIRE number and when you’ll hit it.
Why Coast FIRE Is Powerful for W2 Workers
Traditional FIRE requires aggressive savings rates — often 50–70% of income — to accumulate a full retirement portfolio within 10–15 years. For many W2 employees, that’s brutal.
Coast FIRE requires something much more achievable: get to your coast number as early as possible, then simply cover your living expenses without stress.
After coasting, your financial goal shifts from “save aggressively for retirement” to “break even on current expenses.” This opens doors most aggressive savers keep closed:
- Working part-time instead of full-time (similar to lean FIRE or barista FIRE)
- Taking a career pivot to something more meaningful but lower-paying
- Starting a business without income pressure
- Moving to a lower cost-of-living area
- Raising kids without the anxiety of falling behind
You’ve already won the retirement game. Now you can optimize for life quality rather than savings rate.
The Risks and Honest Caveats
Coast FIRE is genuinely powerful, but it comes with real risks worth naming:
Sequence of returns risk early in coasting. If markets drop 40% shortly after you hit your Coast number and stop contributing, your new portfolio base is 40% smaller — and the compounding has to work from that reduced floor. A multi-year bear market in your early coasting years can delay your actual retirement significantly.
Inflation erodes purchasing power. A 7% real return assumption already accounts for inflation, but if inflation runs hotter than expected for extended periods, your purchasing power at retirement may be less than the nominal number suggests. Plan conservatively.
Life changes the target. Divorce, medical events, having children when you didn’t plan to, a change in lifestyle expectations — all can raise the retirement spending number you were planning around. Your $1.5M Coast FIRE target at 32 might not be adequate if your circumstances change significantly by 45.
Healthcare is the X factor. If you leave W2 employment at your Coast milestone, you lose employer-subsidized health insurance. ACA marketplace plans can cost $600–$1,500/month for a family until you qualify for Medicare at 65. This cost needs to be covered by your “coast” income.
The plan requires patience. Once you’ve hit Coast FIRE and reduced your work intensity, you need to genuinely leave your retirement accounts untouched for decades. This requires both discipline and emotional comfort with market volatility.
Where to Invest Your Coast FIRE Assets
Once you’ve built your coast number, your investment strategy matters. You want broad, diversified, low-cost index funds that compound reliably over 30+ years.
Top platforms for Coast FIRE investing:
| Platform | Zero-Fee Index Funds | Link | Best For |
|---|---|---|---|
| Fidelity | Yes (FSKAX, FTIHX) | fidelity.com | Zero expense ratio index funds + excellent interface |
| Vanguard | Yes (VTSAX, VTIAX) | vanguard.com | Home of index fund investing + low costs |
| Charles Schwab | Yes (SWTSX, SWISX) | schwab.com | SCHB/SCHA index funds + competitive rates |
| M1 Finance (affiliate link) | Yes | m1.com | Automated portfolio rebalancing + lower costs |
All three offer:
– Total stock market index funds (~0.03% expense ratio)
– International index funds (~0.05% expense ratio)
– Bond index funds for stability
– Tax-advantaged accounts (401k, IRA, taxable brokerage)
For Coast FIRE, a simple three-fund portfolio (US stocks, international stocks, bonds in 60/30/10 proportions) compounds reliably over 30+ years with minimal oversight.
How to Calculate Your Coast FIRE Number
Use this step-by-step process:
Step 1: Determine your desired annual spending in retirement (in today’s dollars). Don’t underestimate — be honest about the lifestyle you want.
Step 2: Multiply by 25. That’s your retirement portfolio target (4% rule).
Step 3: Calculate your years to traditional retirement age (65, or whatever you choose).
Step 4: Discount your retirement target backward using the formula:
Coast FIRE Number = Retirement Target ÷ (1.07)^years
Example:
– Annual retirement spending: $80,000/year
– Retirement target: $2,000,000
– Current age: 35, target retirement age: 65 → 30 years
– Coast FIRE Number: $2,000,000 ÷ (1.07)^30 = $2,000,000 ÷ 7.61 = $263,000
At age 35, if you have $263,000 invested, you can stop contributing to retirement and coast to $2,000,000 by 65 — assuming 7% real returns.
Coast FIRE vs. Traditional FIRE
| Factor | Traditional FIRE | Coast FIRE |
|---|---|---|
| Goal | Full portfolio now | Coast number by target age |
| Savings rate required | 40–70%+ | Front-loaded, then normal |
| Work flexibility | Can stop working | Just need to cover expenses |
| Typical timeline | 10–15 years | Depends on age |
| Lifestyle flexibility | Constrained during accumulation | More flexible once coast hits |
| Retirement age | Often 30–45 | Often 50–65 |
Coast FIRE is often more realistic and more livable than the sprint model — and for W2 employees who value lifestyle balance, it’s frequently the better fit. It also relates directly to other FIRE variations: compare it with lean FIRE and Barista FIRE to see which path fits your goals. Read about how to retire at 45 for other realistic early retirement approaches, and how to build a million-dollar portfolio on a $70k salary to understand wealth-building trajectories.
What to Do Once You Hit Coast FIRE
- Stop (or dramatically reduce) retirement contributions. The whole point. Redirect that money toward present-day quality of life.
- Ensure you can cover living expenses with your current or reduced income — without needing investment contributions.
- Don’t touch your retirement accounts. The math only works if you leave the money alone for the full compounding period.
- Protect with insurance. Health, disability, and life insurance become more important once your savings buffer disappears. Don’t get caught under-insured.
- Revisit annually. Recalculate your coast number each year as your expected retirement spending evolves. If you’re significantly ahead of plan, acknowledge it. If market downturns have moved the target, adjust.
Frequently Asked Questions
What happens if the market crashes after I hit my Coast FIRE number?
Your timeline may shift. If you reach your coast number at $300,000 and markets drop 40% to $180,000, you’re working from a lower base and may not hit your target by 65 without additional contributions. However, this is less catastrophic than it sounds — the 30 remaining years still provide significant compounding. A 40% decline followed by 7% annual growth will still get you close to your target. For safety, hit your coast number with a 10–20% buffer above the minimum.
Can I Coast FIRE if I’m in my 50s?
Yes, but the math is tighter. At 50 targeting 65 with a $2M retirement goal, your coast number is around $408,000 (per the table above). If you have that or more invested today, you’re good. If not, you may need to work past 65 or reduce your retirement spending target. Hitting Coast FIRE later is still valuable — it removes the retirement savings pressure for your final working years.
Should I keep my Coast FIRE money in stocks or bonds?
Since your coast money won’t be touched for 15–35 years, keep it in stocks (or 80–90% stocks). Time is your friend. A 60/40 stock/bond portfolio returns ~6.5% real, slightly under the 7% assumption — still plenty to hit your number. Avoid the temptation to shift heavily into bonds or cash after hitting coast. Your 30-year timeline demands equity exposure.
What if I reach Coast FIRE but realize I want to retire earlier than 65?
You have two options: (1) Recalculate — if you want to retire at 60, your coast number at that date needs to be larger. Run the numbers to see what you’d need invested by 60. (2) Continue light contributions — you don’t have to stop completely. Even $300/month for the next 10 years meaningfully accelerates your early-retirement date. Coast FIRE is flexible.
How do I handle healthcare costs before Medicare?
This is the major unknown. ACA marketplace plans typically cost $800–$1,500/month for a family depending on your state and income. Your “coast” income needs to cover this. Some early retirees use health sharing ministries (Liberty HealthShare) as lower-cost alternatives — note these are not insurance and operate differently. Budget $12,000–$18,000/year for healthcare in your coast income planning.
Is 7% real return realistic?
Historically, yes. The U.S. stock market has returned ~10% nominal (7% after inflation) over 90+ years. However, future returns may be lower, especially if valuations remain elevated. Use 7% as a baseline but consider 6% as a conservative scenario. If you hit your coast number at 6% returns, you’re ahead. If you miss and need 8%, you’re behind. Build a small buffer.
The appeal of Coast FIRE is the freedom it creates. You’ve done the hardest part. The math is working for you. You can stop sprinting.
Most people in their 30s and 40s could coast if they realized how close they already are. Run the numbers. You might surprise yourself.
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This article is for informational purposes only and does not constitute financial advice. All return assumptions are illustrative. Consult a qualified financial advisor regarding your specific situation.
