When can you stop saving?

Coast FIRE means you've saved enough in your retirement accounts that, even if you never contribute another pound, compound growth alone will carry your portfolio to your full FIRE number by your traditional retirement age (typically 60-67). Once you hit Coast FIRE, you only need to earn enough to cover current living expenses — no more saving required.

Coast FIRE number = Full FIRE number ÷ (1 + real return rate)^(years until retirement). Example: FIRE target £1.5M, retiring in 30 years at 7% real return → £1,500,000 ÷ (1.07)^30 = £197,000. If you have £197,000 invested today, it will grow to £1.5M by retirement without another contribution.

Your Coast FIRE number is the minimum portfolio size needed today so that compound growth alone reaches your full FIRE target by retirement — with zero additional savings. It shrinks the longer you have until retirement: at 7% real returns, £100K at age 25 becomes £1.5M by 65. Your Coast FIRE number rises sharply as you get closer to retirement.

Full FIRE means your portfolio is large enough to support your expenses indefinitely right now. Coast FIRE means your portfolio will grow to that point on its own by a future date. If your FIRE number is £1.5M at age 60 and your investments will compound to £1.5M by then without additional contributions, you've hit Coast FIRE — even if your current portfolio is only £400K.

A common assumption is 5-7% real (inflation-adjusted) return for a globally-diversified equity index portfolio. Most UK FIRE investors hold a single global tracker such as a FTSE Global All Cap or an all-world ETF (e.g. VWRP / VWRL) inside an ISA or SIPP, rather than picking stocks. Conservative estimates use 4-5%; aggressive use 7%. Lower assumed real returns mean you need more saved today to reach Coast FIRE — the calculator above shows projections only, not guarantees.

Yes — any invested UK pot counts toward your Coast FIRE number: a Stocks & Shares ISA (£20,000/yr allowance), a Lifetime ISA (£4,000/yr with a 25% government bonus), a SIPP, your workplace pension, and any general investment account. The key insight is that money already invested compounds regardless of further contributions. Once you hit Coast FIRE you can stop contributing entirely, shift to lower-stress work, or redirect savings into current lifestyle — your retirement pots grow on autopilot inside the tax wrappers.

The full new State Pension was £11,502 a year in 2024/25 and rises each year under the triple lock. Because it covers a slice of your baseline retirement spending from State Pension age (currently 66, rising to 67), your private FIRE number only needs to fund the gap above it — and your Coast FIRE number falls accordingly. Many UK coasters who plan to retire before State Pension age size their pot to bridge the years until it kicks in, then lean on the State Pension afterwards. Check your forecast at gov.uk/check-state-pension.

Coast FIRE means your saved investments will compound to your full FIRE target without more contributions — you just need to cover current expenses from income. Barista FIRE means you work a low-stress part-time job whose income partially covers current expenses while your portfolio also grows. Both eliminate the need to save aggressively; in the UK, part-time work also keeps you building National Insurance qualifying years toward the State Pension.

Yes — especially for those who start investing early. Saving £100K by age 25 and investing in a broad global index fund at 7% real return reaches £1.5M by age 65 without another contribution. The challenge is saving the initial Coast number, not the decades of growth. Many UK savers can reach Coast FIRE in their 30s or early 40s with consistent early ISA and pension contributions.