Coast FIRE UK: Stop Contributing and Let It Grow

Published 29 March 2026 • 8 min read

Coast FIRE is arguably the most psychologically freeing variant of the FIRE movement. The idea is simple: save aggressively early in your career until your pension and investment pots are large enough that compound growth alone will carry them to your target by traditional retirement age. Then you stop saving for retirement entirely and only need to cover your current living expenses.

Coast FIRE in a nutshell: You have invested enough that, with zero additional contributions, your portfolio will grow to your full FIRE number by a target retirement age (e.g., 60 or 67). You still work, but only enough to cover today’s bills — no more saving required.

How to Calculate Your Coast FIRE Number

The formula is: Coast FIRE Number = FIRE Number ÷ (1 + growth rate)^years until retirement

Assuming 5% real (after-inflation) annual growth and a target FIRE number of £625,000 at age 67:

Current Age	Years to 67	Coast FIRE Number
25	42	£80,000
30	37	£103,000
35	32	£131,000
40	27	£167,000
45	22	£214,000
50	17	£273,000

A 30-year-old who has £103,000 invested today can theoretically stop all retirement saving and still have £625,000 at 67 — enough for a moderate retirement with the State Pension.

Important caveat: These projections assume 5% real returns sustained over decades. Actual returns vary year by year. Markets can stagnate for long periods. Coast FIRE is a useful mental model, but continuing even small contributions provides a valuable safety margin.

Coast FIRE With the UK State Pension

The State Pension (£11,502/year) is effectively a guaranteed Coast FIRE benefit that every UK worker builds. If you have 35 qualifying NI years, the State Pension is already secured — you are already coasting towards a baseline retirement income.

This means your Coast FIRE number only needs to cover the gap between the State Pension and your target retirement income. For a moderate retirement of £25,000/year, you need your investments to provide £13,500 — a pot of roughly £337,500 at 67.

What Life Looks Like After Coast FIRE

Once you hit your Coast FIRE number, your relationship with work fundamentally changes:

Career flexibility — take a lower-paid job you enjoy, go freelance, or work part-time
No savings pressure — your entire salary covers current expenses and lifestyle
Reduced stress — knowing your retirement is already funded brings enormous peace of mind
Sabbaticals — take extended breaks knowing your pension continues growing untouched

Coast FIRE vs Other FIRE Variants

Type	Still Working?	Still Saving?	Difficulty
Full FIRE	No	No	Hardest — largest pot needed
Barista FIRE	Part-time	No	Moderate
Coast FIRE	Yes (any job)	No	Easiest — smallest initial pot
Lean FIRE	No	No	Moderate — requires frugality

UK-Specific Coast FIRE Tips

Maximise employer pension matching early in your career — it turbo-charges your Coast FIRE number
Use your ISA allowance (£20,000/year) while you are still saving aggressively
Check your State Pension forecast to factor in guaranteed retirement income
Even after reaching Coast FIRE, consider opting out of additional pension saving strategically rather than immediately
Keep NI contributions going to build your full 35-year State Pension record

Already at Coast FIRE and not sure? A pension adviser can review your current pots, projected growth, and State Pension entitlement to confirm whether you have reached your Coast FIRE number. Get matched for free →

Key Takeaways

Coast FIRE means your investments will grow to your retirement target without further contributions
The earlier you start, the lower your Coast FIRE number — a 25-year-old needs just £80,000
The UK State Pension reduces the gap your investments need to fill
After Coast FIRE, you only need to earn enough to cover current living expenses
Continue building NI years for the full State Pension even after reaching Coast FIRE
Consider maintaining small contributions as a safety buffer against market underperformance