Coast FIRE Calculator: When Can You Stop Saving for Retirement?

What Is Coast FIRE?

Coast FIRE is the point where your existing investments will grow to your full retirement number by your target retirement age – without contributing another dollar. You have saved enough. Time and compounding do the rest.

The FIRE community breaks down into several stages, and Coast FIRE is the first meaningful milestone:

• Coast FIRE: Your investments will compound to your retirement number on their own. You still work, but only to cover current expenses. No more saving required.
• Barista FIRE: Similar to Coast FIRE, but specifically refers to taking a low-stress job (like a barista) that provides benefits, especially healthcare.
• Lean FIRE: Full financial independence at a minimal spending level ($25K-$45K/year).
• Regular FIRE: Full financial independence at a comfortable spending level ($45K-$80K/year).
• Fat FIRE: Full financial independence with premium optionality ($150K-$300K+/year).

Coast FIRE is different from the others because you are not done working. You are done saving. That distinction matters more than most people realize, because for many people the saving is the hard part – the thing that forces them to stay in high-paying, high-stress jobs.

How the Coast FIRE Number Works

The math is straightforward. You need two numbers:

1. Your FIRE number – how much you need at retirement. This is your annual spending divided by your withdrawal rate, adjusted for taxes. At $80,000/year spending, 4% withdrawal rate, and 15% tax: ($80,000 / 0.85) / 0.04 = $2,352,941.

2. Your Coast FIRE number – how much you need TODAY so that compounding reaches your FIRE number by retirement. This is your FIRE number divided by the compounding factor. At 2.4% real return (5% nominal minus 2.5% inflation) with 30 years to grow: $2,352,941 / (1.024)^30 = $1,152,825.

If your current savings exceed your Coast FIRE number, you are coasting. Every dollar you save beyond this point accelerates your retirement date or increases your retirement spending – but it is no longer required.

Why Coast FIRE Matters More Than You Think

It changes what “enough” means today

Most financial advice focuses on the gap between where you are and full FIRE. That gap can feel insurmountable – especially for someone in their 30s looking at a $2.5M target. Coast FIRE reframes the question: you do not need $2.5M today. You need $200K-$400K today, and then you can exhale.

It makes career risk rational

The biggest career moves – starting a company, switching industries, going back to school, taking a sabbatical – all feel risky when your retirement depends on your current income. Once you hit Coast FIRE, that risk evaporates. Your retirement is funded. Your current income only needs to fund your current life.

It is achievable decades before full FIRE

A dual-income couple saving $50K/year can hit Coast FIRE in their early 30s. That is 30+ years of career freedom that full FIRE cannot offer. The person who hits Coast FIRE at 32 and takes a 50% pay cut to do meaningful work may end up happier than the person who grinds until 45 for full FIRE.

Coast FIRE Numbers by Age (Targeting $2M at 65)

These numbers show what you need saved at each age so that compounding alone reaches a $2M FIRE number by age 65, assuming 5% nominal returns and 2.5% inflation (approximately 2.4% real return):

• Age 25: $780K – 40 years of compounding, maximum time advantage
• Age 30: $870K – still substantial compounding runway
• Age 35: $975K – the window where most aggressive savers cross the line
• Age 40: $1.1M – compounding has less time, so you need more upfront
• Age 45: $1.2M – 20 years left, the number is closing in on the target
• Age 50: $1.4M – 15 years of compounding, real return does less heavy lifting
• Age 55: $1.6M – at this point, Coast FIRE and near-FIRE start to merge

The pattern is clear: every five years you wait, you need roughly 12-15% more. Time is the most powerful variable in this equation, and it only moves in one direction.

The Coast FIRE Lifestyle

What does life actually look like after Coast FIRE? Here are the most common paths:

The downshift. You stay in your field but move to a less demanding role. Senior engineer to mid-level at a smaller company. Partner track to senior associate. Director to individual contributor. The pay cut does not matter because you are not saving anymore.

The barista path. You take a simple, low-stress job that covers expenses and provides benefits. Especially relevant in the US, where health insurance is tied to employment. A part-time job at Starbucks or Costco can provide healthcare while you coast.

The passion project. You start the business, write the book, teach the class, build the thing you have been thinking about for years. It does not need to be profitable immediately – or ever – because your retirement is already handled.

The geographic shift. You move somewhere cheaper and work remotely or locally. Your Coast FIRE number does not change (it is based on future retirement spending, not current expenses), but your current expenses drop, making it even easier to cover them with lower income.

Common Mistakes with Coast FIRE

Using nominal returns instead of real returns. If you use 7% instead of 4.5% real (after inflation), you will dramatically underestimate your Coast FIRE number. A $200K portfolio growing at 7% nominal for 30 years reaches $1.52M. At 4.5% real, it reaches $748K. The difference is not rounding error – it is the difference between coastable and not.

Forgetting taxes on withdrawals. Your FIRE number is not 25x your spending. It is 25x your gross withdrawal, which must cover taxes. At 15% tax, you need to withdraw $94,118 to spend $80,000. That adds 18% to your required FIRE number.

Ignoring lifestyle inflation. Your Coast FIRE number is based on a retirement spending target you set today. If your lifestyle inflates between now and retirement, the real target is higher and you were never actually coasting.

Assuming you will actually stop saving. Many Coast FIRE achievers find it psychologically impossible to stop saving. If that is you, recognize that hitting Coast FIRE is still meaningful – it means every additional dollar saved is bonus, not necessity.

Frequently Asked Questions

What is Coast FIRE?

Coast FIRE is the point where your existing investments will compound to your full retirement number by your target retirement age, without any additional contributions. You still work to cover current expenses, but you never need to save for retirement again.

How much do I need for Coast FIRE?

It depends on your age, target retirement age, desired retirement spending, withdrawal rate, and expected returns. A 35-year-old targeting $80K/year retirement spending at 65 needs roughly $215K-$280K today (depending on assumed returns). Use the calculator above with your specific numbers.

Is Coast FIRE the same as Barista FIRE?

They are closely related. Coast FIRE is the financial milestone – having enough that compounding handles retirement. Barista FIRE specifically refers to the lifestyle choice of taking a low-stress job (like a barista) after hitting that milestone, often for health insurance benefits.

What is a good age to reach Coast FIRE?

Most aggressive savers reach Coast FIRE in their late 20s to mid 30s. But there is no “right” age. Reaching Coast FIRE at 45 still gives you 20 years of career freedom. The value of Coast FIRE is proportional to how many working years remain after you reach it.

Can I reach Coast FIRE with a normal salary?

Yes. A household saving $30K-$50K per year starting in their mid 20s can reach Coast FIRE by their early to mid 30s. The key is starting early – the math rewards time far more than it rewards high income. Someone saving $30K/year from 25 to 33 can coast, while someone saving $50K/year from 35 to 45 may still not be there.

What happens if the market crashes after I start coasting?

Market crashes are temporary. Your Coast FIRE number accounts for average returns over decades, and historically, every 30+ year period in the US market has produced positive real returns. A crash in year 1 of coasting is stressful but recoverable if you have 20+ years until retirement. If you have less runway, consider a small safety margin above your Coast FIRE number.