What is Coast FIRE? The Milestone Worth Aiming For

Full financial independence can feel a long way off. Coast FIRE is a nearer, more motivating milestone on the way there. It is the moment your invested pot is already big enough to grow into your full retirement number on its own - meaning you could stop saving entirely and still retire on time.

What does Coast FIRE actually mean?

FIRE stands for Financial Independence, Retire Early. Coast FIRE is reaching the point where, if you never invested another penny, compound growth alone would carry your existing investments up to your retirement target by your chosen age. From that point, your retirement is effectively on autopilot - you only need to earn enough to cover your current living costs.

It is a powerful psychological milestone. Hitting Coast FIRE means the heavy lifting of saving is done. You can ease off, switch to a lower-paid but more enjoyable job, go part-time, or simply stop stressing about pension contributions.

How is Coast FIRE calculated?

Your Coast FIRE number is your full retirement number discounted back to today at your expected investment return. In plain terms, it is the amount that, left alone to compound until your target age, would grow into the pot you need.

Because of compounding, the Coast FIRE number is much smaller than the final target, and it gets smaller the younger you are. An example with a £750,000 target and a 5% real return:

• At 30, retiring at 60: you would need roughly £174,000 invested today to coast.
• At 40, retiring at 60: you would need roughly £283,000.
• At 50, retiring at 60: you would need roughly £460,000.

The earlier you start, the less you need to have already saved before growth can take over. Our Coast FIRE calculator works out your number and the age you reach it from your own figures.

Coast FIRE vs regular FIRE

The difference is whether you still need to work. With regular FIRE, you have enough invested to live off your portfolio now and can stop working. With Coast FIRE, you have enough that you no longer need to save, but you still work to cover day-to-day spending while the pot grows itself to the full number. Coast FIRE almost always comes first.

A word on UK pension access

Coast FIRE is usually framed as a single pot, but in the UK some of your money may be locked in a pension until age 57. If you want to retire earlier than that, you also need accessible savings to bridge the gap - see the pension bridge. Coast FIRE tells you the saving is done; the bridge tells you whether you can actually stop work when you want to.