Coast FI Explained [includes Coast FIRE Calculator]

Coast FI is becoming increasingly popular as a Financial Independence strategy all the time. More and more people are realising how powerful the lifestyle benefits of this approach are. So it is no surprise that the demand for our free Coast FIRE Calculator has been through the roof recently and that I receive reader questions on Coast FI regularly.

In this article, we’ll cover the ins and outs of Coast FI. I’ll also show you how you can calculate your Coast FI number. Plus, I’ll share our popular Coast FIRE calculator.

What is Coast FI?

Coast FI is the point at which you have saved enough to get to Financial Independence by the time you reach the traditional retirement age through compound interest alone. Once you reach this point, you don’t have to make any further contributions to your retirement portfolio. You could stop saving altogether, and as long as you don’t touch your investments, your portfolio will generate enough income in retirement – thanks to the magic of compound interest.

To me, Coast FI really is THE most important milestone on the path to Financial Independence. Once you get there, you don’t have to save another dollar, and you will still be ok later on. From that point on, you only need to earn enough to cover your monthly expenses. How powerful is that?

Here is a visual illustration of Early Retirement (“traditional” FIRE) vs Coast FIRE:

Early Retirement visualised.
With “traditional” FIRE, you work full-time and save as much as you can until you reach FI (and retire early if you want to).
Coast FI visualised
With Coast FI, you work full-time until you reach your Coast FI number. After that, you can semi-retire and work only to cover your monthly expenses.

A typical Early Retirement plan (standard FIRE) usually consists of two phases: 1. Your full-time career and 2. Early Retirement. Coast FIRE is a 3-phase approach: 1. Your full-time career, 2. Semi-Retirement, 3. Full Retirement (Financial Independence).

Just think about how many people in their 50s and 60s worry about not having enough money in retirement. Once you get to Coast FIRE, that is one thing you don’t ever have to be concerned about anymore. That’s why this financial milestone is so important – not just for people who want to retire early, but for anyone who wants to retire at all.

Is Coast FI the Right Strategy for You?

We will all pass the Coast FI at some stage on our path to FIRE. For some, it’s just a milestone (like the first 100k, for example). For others, it is the first potential “exit point” from the 9 to 5 grind. While you cannot stop working altogether when you reach Coast FI, you can semi-retire and make significant changes to improve your quality of life and create more balance.

So what are some reasons to consider using Coast FIRE as an exit from the rat race?

  • You simply don’t like your job and want to make a change without risking your financial future.
  • You want to work less and live more as soon as possible.
  • You have children and want to prioritise spending time with them while they are young.
  • You want to start your own business.
  • You don’t want to retire completely for a long time but want more time for hobbies and projects sooner rather than later.

Different people have different goals. The FIRE movement is very diverse. That’s why it is important to consider all the different types of Financial Independence when you make a plan for your (financial) future. I believe that everyone should at least consider Coast FI as an option. It is a great choice for anyone who, for whatever reason, wants to or needs to stop working full-time.

It is also possible to use these principles to create your own semi-retirement plan and reach FIRE at your target retirement age (e.g. 50) instead of your traditional retirement age (e.g. 67). This is exactly what Mr. Flamingo and I have done. We wanted to leave the rat race as soon as possible, but we ALSO wanted to reach FIRE long before our traditional retirement age. Tweaking Coast FI principles to create our own approach – Flamingo FI – has allowed us to do just that. More on this in the Advanced Coast FIRE Strategies section below.

How to Calculate Your Coast FI Number

Calculating your Coast FI number is a bit more complicated than figuring out your regular FIRE number, where you simply multiply your annual living expenses by 25. The reason for this is that your current age is the most important factor for this financial independence approach. The younger you are, the lower your Coast FI number.

The Coast FIRE Formula

Note: If you are not a math person, you can go straight to the next paragraph and use the calculator to figure out your Coast FI number!

This is the formula to calculate your Coast FI number:
Coast FI number = FI number * (1 + Interest Rate) ^ -Number of Years to Retirement

Here is an example:
John is 45 now and wants to retire at 65 – 20 years from now. His FI number (25x annual retirement expenses) is $1,000,000. He thinks his investments will grow by 7% after inflation per year.

John’s Coast FI number = $1,000,000 * (1 + 0.07) ^ -20 = $258,419

So John could stop saving straight away, get a part-time job in a café (this is why Coast FI is mistakenly called Barista FIRE sometimes) and still enjoy a comfortable retirement and live off the passive income from his investments once he turns 60.

One thing to remember about your Coast FI number is that it is not static, it is a moving target. This is because your Coast FI number will be higher the closer you get to retirement.

The Coast FIRE Calculator

If the Coast FIRE formula above makes your head spin, you are not alone. The easiest way to calculate your Coast FI number is to use our free all-in-one Semi-Retirement Calculator.

This calculator lets you calculate

  • your current Coast FI number for both your traditional and target retirement age
  • your future Coast FI number, and the age you’ll get there (again, for both your target and traditional retirement age).

In addition, this calculator also shows your Flamingo FI and traditional FIRE numbers and ages.

To download the calculator, you can enter your details in the form below:

You can find out more about the calculator and what all the results mean here.


Whether you use our calculator or the formula above to calculate your Coast FI number manually, you will have to make some assumptions. It makes sense to keep the assumptions you use for these calculations a bit more conservative so that you don’t run into problems later on.


While we used to see really high inflation rates regularly 30-40 years ago, central banks around the world have decided that 2-3% is a good target and have been successful in keeping inflation below 3% for a long period of time. Yes, inflation is currently a little out of control and has many in the personal finance space worried. However, in our opinion, there is no reason to believe the rates won’t go back down to the long-term average sooner or later. That’s why we use 2-3% for our calculations, but you might see things differently and use a different number.

Expected Investment Return

It is impossible to predict the investment returns we’ll achieve over the next 30+ years. The share market has returned an average of just over 11% since 1950 (this is based on the S&P 500 and may or may not be different for other stock markets around the world). You can check this data for different historical timeframes yourself here. After inflation (see above), average real returns were around 7.5-8% per annum. If we only look at the last 40 years, the returns are actually a bit higher. Similarly, it is not possible to predict the future returns of other asset classes like property.

This means that for Coast FI, it is reasonable to be quite conservative when making assumptions about future investment returns. Many people in the personal finance community feel comfortable using 7% inflation-adjusted returns We feel comfortable using 7% inflation-adjusted returns (so 9-10% returns minus 2-3% inflation over the long run) for our own calculations and projections). Others use 5% or even 3% to be on the safe side.

Safe Withdrawal Rate (SWR)

Most people in the FIRE community use the popular 4% safe withdrawal rate for their return assumptions. Depending on how conservative you are, you could, of course, use a lower or higher SWR. If you are over 65, most retirement advisors actually recommend using 5%.

Bill Bengen, the creator of the 4% rule, actually changed it a while ago and raised it to 4.5%. Keep in mind that his calculations are based on a 30-year retirement only, so we are more comfortable sticking with the “traditional” 4% rule. Others in the community prefer to use an even lower number (3%-3.5%).

I found this episode of the Choose FI podcast about flexible spending rules in retirement and safe withdrawal rates really helpful.

Living Expenses

Since you’ve already made assumptions about inflation rates, you can use your annual expenses in today’s dollars for your calculations. This doesn’t mean you should use your current expenses. Chances are, your life will look quite different when you actually get to the retirement part of your Coast FI plan. Spend some time thinking about what your life will be like when you retire, where you will live, what you will be doing, etc. – and how much this will cost. Depending on where in the world you live, there are some pretty good resources that can give you an idea of general living expenses for retirees.

Run The Numbers!

Now that you have made all the necessary assumptions, you are ready to calculate your Coast FI number and age. As mentioned above, you can either use our calculator or the Coast FI formula for this.

A word of caution: When I originally published this article in 2019, there were not many articles (or calculators) about this topic. There are now many different resources and also tools/calculators out there. I often get emails from readers who are confused because they get ten different results from ten different calculators. It is always a good idea to check the actual math behind some of these tools and also what kind of assumptions are pre-set. Just because someone has a calculator on their website doesn’t mean that they understand it (or even that they build it themselves…). Don’t just blindly trust a random tool from the internet to tell you when you can retire!

Coast FI vs Barista FIRE

Coast FI and Barista FIRE are the same thing, right? Wrong! This is a common misconception. I actually thought these were just different terms for the same concept for a long time myself.

While both Coast FI and Barista FI use semi-retirement strategies, there is one big difference.

Coast FIRE will lead you to Financial Independence eventually. In contrast, with Barista FI, you most likely will never be able to fully retire. The reason is that with Barista FI, you draw some passive income from your investments and cover the shortfall you need for your ongoing expenses by working (part-time). This means that your investments will most likely never grow into the nest egg you would need to retire completely.

Coast FIRE vs Barista FIRE
Coast FIRE and Barista FIRE are similar but definitely not the same thing!

Since I realised this, I have stopped considering Barista FI a real alternative to FIRE. It really isn’t a type of Financial Independence but more of a perpetual semi-retirement strategy. That doesn’t mean it isn’t a valid choice for many people, it’s just important to know that you will have to make alternative plans for old age with this type of strategy.

Coast FI vs Flamingo FI

I often get asked what the difference between Coast FI and Flamingo FI is. Flamingo FI could be described as a variation of Coast FI. With Flamingo FI, you will reach FIRE after ten years (if your investments generate inflation-adjusted returns of 7%). For most people, this will be a lot sooner than if they go the Coast FI route.

Coast FI vs Flamingo FI
The major difference between Coast FI and Flamingo FI is the length of the semi-retirement phase.

Both Coast FI and Flamingo FI are milestones on the way to full FIRE. At the same time, both are potential exits on the road to FIRE that you can take if you can’t or don’t want to soldier on in a full-time career until you hit your magic number. Exiting at either Coast FI or Flamingo FI is like getting off the highway and taking a leafy country road to get to your destination at a slower, more relaxed pace.

In the case of Coast FI, you stay on the country road until you reach the standard retirement age. In the case of Flamingo FI, you should get to your destination after about ten years. The alternative is to stay on the highway and race to FIRE – it’s all up to you. What I want to stress is that there are many roads that lead to FIRE, and everyone should make a conscious decision about which road is the right one for them and their family.

We would like to reach FIRE (and be able to stop working completely if that’s what we feel like doing) before the traditional retirement age. That’s why Flamingo FI is a better exit strategy for us. We are now officially semi-retired and loving it. Everyone is different, though, and Coast FI certainly is a great option for many people.

Coast FIRE vs Lean FIRE and Fat FIRE

A common misconception is that Coast FIRE is a type of Financial Independence like Lean FIRE and Fat FIRE. I often receive questions from people like “Should I aim for Coast FI, or is Fat FI better?”. As you’ve probably figured out by now, these concepts are not mutually exclusive.

Lean FI is Financial Independence on a small (lean) budget. Fat FI is the complete opposite – Financial Independence on a generous budget that allows for plenty of luxuries and travel.

Coast FIRE, on the other hand, is just a method to get to Financial Independence – Lean, Fat or anything in between. So you could coast to Fat FI just like you would to regular FIRE. It just means that your FIRE number will be pretty big, and it will take a long time to get there.

Remember, Lean FI, regular FIRE and Fat FI are destinations. Coast FIRE is a strategy you can use to get there.

Advanced Coast FIRE Strategies

Above I’ve described two potential exit points on the road to Financial Independence: Coast FI and Flamingo FI. You could also use the principles described in this article to create your own approach.

We picked the “50% to FI” point (aka Flamingo FI) because ten years of semi-retirement followed by Financial Freedom felt like a great balance for us.

I’ve created the Coasting Exit Points grid below to give you an idea of how long your semi-retirement stage will be at various exit points (in % terms) – depending on your expected portfolio return. If your expected return is 7%, then you could exit the rat race at the 70% mark and get to FI through compound interest in just over five years.

When you think about it in this way, every exit point is a version of Coast FI – including traditional FIRE (where you exit at 100%)!

Coast FIRE grid

Benefits of Coast FIRE

The benefits of this strategy are obvious – you only have to work for a few short years before you can move to part-time work. You can leave your high-stress job, don’t have to worry about the next promotion and can start planning for the life you really want. You can also stop stressing about and obsessively tracking your net worth. Coast FI makes the most of the power of compound interest compared to all other types of Financial Independence. Plus, with this approach, you get to enjoy the benefits of the semi-retired life for a very long time. Simply put, when you coast to Financial Independence, you get (some of) your time back sooner so you can get on with life.

Risks – Is Coast FI Dangerous?

Yes and no. Coast FI relies on compound interest. There is absolutely no guarantee you will get the market returns you need (and assumed you would get when you ran the numbers). If you hit this goal at a young age and then don’t look at your investments again until you are close to retirement age, you might be in for a rude shock. If your nest egg is nowhere near as big as you thought it would be, you might be in trouble, especially if you can’t go back to work (because of your age or health).

There is a simple solution to this: Simply re-Coast FIRE every year! Make it a habit to calculate your current Coast FI number once a year to check if you are on track. If your portfolio value is lower than your current Coast FI number, you should top up your investments. The good thing is that you are semi-retired, not fully retired, so it should be easy to pick up a little extra work for a little while. You might only need to add a few thousand dollars that will make a big difference over time.

So yes, Coast FIRE can be a dangerous strategy if you don’t make sure you stay on track and top up your investments if needed. This is easily mitigated by re-calculating your Coast FIRE number and monitoring your portfolio performance on a regular basis.

Life after Coast FI

Once you hit this milestone, you have a plentitude of options. From now on, you can coast to Financial Independence. Your portfolio will do the hard work for you, and you are free to get on with life.

If you want to, you can semi-retire and work part-time. But remember, you don’t have to stop working in your full-time career. You could also keep saving and investing for a few more years to get closer to FIRE before you move to part-time work.

If you decide to semi-retire, here are some ideas to get you started. You could…

  • Take a mini-retirement (aka sabbatical)
  • Start your own business
  • Travel and work as a digital nomad
  • Become a freelancer
  • Volunteer
  • Take a more rewarding job, even if it pays less
  • Simply work for your current employer on a part-time basis
  • Go back to uni part-time or take a course in a field that interests you

Check out my list of 26 lifestyle options you can enjoy before you reach full FI for some inspiration!

Once the financial pressure is off, there is a whole world of options, so take some time to make a life plan that works for you.


Coast FIRE is one of the first and arguably the most powerful milestone on the path to Financial Freedom. It gives you options and the peace of mind that you’ll be ok when you reach the traditional retirement age. Coast FI unlocks the benefits of semi-retirement and allows you to spend more time with the people you care about and on projects that are important to you.

While using this strategy means that you will have to work in some capacity until you reach retirement age, it is a great option for those who don’t want to stop working for a long time. There are also tweaks and alternative strategies (like Flamingo FI) that you can use to speed up your journey to FIRE without giving up the freedom semi-retirement offers.

Don’t forget to download our free Coast FIRE Calculator to see how soon you can start coasting to the finish line!

Is Coast FI a strategy you are considering as an alternative to Early Retirement? What are your thoughts on alternatives like Flamingo FI? Let us know in the comments below!

28 thoughts on “Coast FI Explained [includes Coast FIRE Calculator]”

  1. This is very motivational to see that we have so many options on our way to FIRE. Personally I like the the Flaningo FI option compared to the Coast FI option, for the fact that I have saved up more of a security buffer in case things in the market go pear shaped. Love the Coast FI icon by the way in the graph!

  2. Hi MF, long time lurker on your blog, love your content. I am seriously considering coastFI for myself. I was made redundant a few months ago. Plus I am struggling with some semi permanent health issues that get worse when I am stressed. Don’t know how much longer I can / want to keep hustling for FIRE and would also be ok with working part time. I’m 43 with a decent nest egg but nowhere near FIRE. Past my coast fi number however!

    • Hi Firebum,
      Thanks for your comment! Sorry to hear you aren’t doing too well at the moment. Congratulations on reaching Coast FI! I don’t know your full story but it sounds like you could definitely downshift a little and enjoy the perks Coast FI has to offer.

  3. So that’s what it’s called! Been ‘Coasting’ (on the Coast) for 10 years now… still love my job but also love spending time with my 2 kids and all the other things that define a balanced life. Knowing I only need to work enough to pay the day-to-day bills (and that life beyond 60 is taken care of) is very liberating; and who knows… I might not stop then either.

  4. Thanks for commenting Burrow! Your lifestyle sounds fantastic. Would you mind elaborating a little on your story? I’m sure a lot of readers (Mr. Flamingo and I included) would love to hear more about how you are coasting on the coast!

    P.S.: I’m glad you finally have found out what your lifestyle is called! 😉

    • I got lucky! I earned a decent income straight out of uni and learned the principles of (what was later to become) FIRE in those early years. Being naturally frugal, I had a high savings rate and invested it all in growth assets – in and out of super. Time (and healthy returns) has done the rest.

      The interesting thing is that I was always keen to RE. But as I drew closer to FI, my life gained more balance and the desire to retire slipped away. Instead, I now work part-time, earn enough to cover day-to-day expenses and know my future is taken care of.

  5. Brilliant post, very liberating to see how many variations of financial independence are available than just a hard and fast FIRE (25 x) metric.

    Personally, I’m aiming for under 10 years so the Flamingo FI number is lower than the Coast FI number!

    Keep it up.

    • Thanks Fire Park! There is a whole universe of options outside that metric and I think lots of people get discouraged because they think standard FIRE is the only way. We use more conservative growth assumptions for our Coast FI calculations, so our Coast FI number is also really close to our Flamingo FI number.

      • Does coast fire money have to be outside of Super? If in and out of Super does count we are almost there! That would be a relief as with 4 kids I would love to know we are on track! No doubt there are some things ahead that’ll knock us off course! Having said that neither me or my husband have worked full time since a brief stint in 2017! Our house is almost paid off (regional Vic!). In our mid 30s I feel we are doing ok… reading FIRE stories makes me think we’ve done it all wrong…yet it usually feels in good balance! Having said that our eldest kid is almost a teen and the youngest is not yet one, fair to say over a decade ago we decided raising awesome people is our real job!

    • Great comment Kim. This has framed how I feel perfectly, and why I’m so excited I discovered this concept today.

      I’m not paying off debt, but somehow, I’ve made my saving for the future via investing, feel like a “debt”.

  6. Hi Money Flamingo,

    I’ve started reading your blog after it was recommended by the Spaceship app and been loving it so far!

    Flamingo FIRE resonates with me because like you said, it allows you to work a job you enjoy sooner than traditional FIRE, and it’s a smoother transition out of regular work.

    I love the graphical comparisons of Coast vs Flamingo vs traditional – with flamingo, should there be two flamingos worth of time before I come drops to zero, to reflect that you get to full FI faster than Coast, yet slower than traditional?

  7. Nice one!
    I like to refer to the Coast Fire idea as the Opera House (i.e. how the available portfolio looks on a graph) approach.
    You have your pre-retirement funds you draw down on until you can access your super, the graph of available funds then spikes back up & the drawdowns start again.
    Really easy to understand, particularly when a significant portion is in super (we’re in the same boat as you).

    • I love this visual image!! “Classic” Coast FI doesn’t have a pre-retirement drawdown phase, so I guess this would apply to an adapted Coast FI approach (like Aussie Firebug’s 2-stage strategy). Great way to think about it!

  8. Amazing! Thanks for sharing this fantastic resource! I don’t know if you remember me from our email conversation last year. I really appreciate how generously you share all of this information. Laura ❤

  9. Hi there,

    I have a question about the calculator – once you fill out all the information and it gives you the Coast FI number (for your TARGET retirement age), is this number the amount you should have invested at your current age to be able to retire by your target retirement age? Or is it the number you need to have invested by the time you reach you target retirement age?

    • Hi Carly, your Coast FI number is the amount you should have invested at your current age. The amount you need invested when you get to your target retirement age is your FIRE number (in 2022 dollars, so it will be higher in real terms when you get there). I hope this makes sense!


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