Coast FIRE is a version of the Financial Independence Retire Early movement where you save enough early that your investments grow to fund retirement with no further contributions.
Once you reach your Coast FIRE number, you only need to earn enough to cover today’s living costs. That lets you move to a lower-stress or part-time job and stop adding to your pension or ISA. Compound growth does the rest until normal retirement age. The Coast FIRE number is far lower than a full FIRE target, which makes it achievable for more people.
This guide covers how Coast FIRE works, how to build a strategy around it, and the risks to plan for. If you want your personal number first, run it through our Coast FIRE calculator and come back.
Table of Contents
What is Coast FIRE?
Coast FIRE (Coast Financial Independence, Retire Early) is the point where your invested pot is already big enough that, left completely alone, compound growth will turn it into a full retirement fund by your target retirement age.
You still work until then, because you need to cover your day-to-day living costs. The difference is that your job no longer has to fund your future, only your present. That is the “coasting” part. Many people use it to drop to part-time hours, switch to a lower-pressure role, or finally do work they enjoy without worrying about the salary ceiling.
The maths is what makes it accessible. A 30-year-old aiming for a £600,000 pot at 65 needs roughly £110,000 invested today (assuming 5% growth after inflation). No further saving required. The same pot built from scratch at 50 would take heavy contributions every month.
Coast FIRE vs the other types of FIRE
All FIRE variations share the same idea: build investments that make work optional. They differ in how much you need and when you stop working.
- Coast FIRE: save hard early, then stop. Work covers your living costs until retirement while the pot grows untouched. The smallest target of any FIRE type.
- Barista FIRE: semi-retire early and use part-time work to top up your income while you start leaning on your portfolio. You draw on your money sooner than with Coast FIRE.
- Lean FIRE: retire fully on a deliberately frugal budget, so the target pot is smaller.
- Traditional FIRE: save roughly 25 times your annual expenses, then retire early on the 4% rule.
- Fat FIRE: retire early without giving up the luxuries, which means the biggest pot of all.
If you are new to the movement, start with our guide to the FIRE movement.
How to build your Coast FIRE strategy
1. Find your Coast FIRE number
Everything starts with the number: your full retirement target, discounted back by the growth you expect between now and retirement. Our Coast FIRE calculator does this for you, including UK pension quirks like which pots to count.
2. Audit your spending
You need two figures: what your lifestyle costs now (the income your coasting job must clear) and what it will cost in retirement (which sets the target). A simple household budget surfaces both, and usually finds money you can redirect into investments. For help staying consistent, check out our own Gains App.
3. Maximise your savings rate until you hit the number
Coast FIRE front-loads the effort. The faster you invest in the early years, the sooner you can ease off. Automate contributions on payday, clear expensive debt first, and consider passive income streams to speed the journey up.
4. Invest for long-term growth
Your plan assumes decades of compounding, so the money needs to be invested, not sitting in cash. For most people that means a diversified portfolio of low-cost index funds inside tax wrappers like a pension or stocks and shares ISA. If you are unsure, speak to a regulated financial adviser.
Living the Coast FIRE lifestyle
Hitting your number changes the question from “what pays most?” to “what do I actually want to do all day?”. Some people go part-time. Others switch to charity work, freelancing, or a small business they always wanted to try. The only requirement is that it covers your living costs without burning you out, because you will be doing it until retirement age. It looks different for everyone: Neil Invests reached Coast FIRE in his early 40s and is now coasting towards retiring at 50.
The discipline does not end at the number, though. The plan only works if your spending stays roughly where you projected it. Lifestyle creep, quietly upgrading your life every time income rises, is the most common way people break their own Coast FIRE maths.
The risks of Coast FIRE
Coast FIRE is a bet on decades of investment growth, so treat these risks seriously:
- Returns may disappoint. Your number assumes a growth rate. A long stretch of poor markets, especially early on, can leave the pot behind schedule. Review your number every year or two rather than setting and forgetting.
- Inflation erodes the target. Work in real (after-inflation) terms. A retirement budget set in today’s money needs a growth assumption net of inflation, or the pot will look on track while quietly falling behind.
- Life changes. Redundancy, illness, children, or divorce can change both your costs and your ability to coast. Keep a proper emergency fund as the buffer between a bad year and a broken plan.
- UK pension rules move. Most Coast FIRE pots sit largely in pensions, and the earliest access age rises from 55 to 57 in 2028. If you want flexibility before then, make sure some of your money grows in an ISA you can reach.
Final thoughts on Coast FIRE
Coast FIRE is the most forgiving version of financial independence: one hard sprint of saving, then decades of freedom to choose work on your own terms. Your Coast FIRE number is far smaller than a full FIRE target, and for a young saver it can be surprisingly reachable.
Start by calculating your Coast FIRE number. Even if you are years away, knowing the number turns a vague ambition into a target you can actually hit.
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Disclaimer: Content on this page is for informational purposes and does not constitute financial advice. Always do your own research before making a financially related decision.
