Coast FIRE Calculator UK (£) — ISA, Pension & State Pension
Work out your Coast FIRE number in pounds — when you can stop saving and let your ISA and pension compound to retirement.
Related Calculators
Need a different calculation? Try these:
Quick Calculator
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Coast FIRE by Age
See benchmark numbers for every age from 25 to 55
For Couples
Calculate with dual incomes and joint expenses
With Pension
Subtract pension income from your target — gap years included
UK / Canada / India
Tax rules and currency adjustments for Canada, India, and the UK
Is Coast FIRE Worth It?
Honest pros, cons, and risks to help you decide
What this UK Coast FIRE calculator works out
What it calculates
Coast FIRE is the point where you can stop saving for retirement. This UK Coast FIRE calculator gives you that number in pounds. Your pot isn't big enough to retire on today, but if you leave it untouched it will grow to your full retirement target by age 67. It is different from full FIRE, which is the much larger amount you'd need to retire right now.
The formula, in plain English
Two steps do all the work:
- 1.Full FIRE number = annual spending ÷ 4%. This is the pot you'd need to live off forever using the 4% safe withdrawal rule.
- 2.Coast FIRE number = Full FIRE ÷ (1 + real return) raised to the years left to retirement. Real return is your growth after inflation.
We use a 6% expected return and 3% inflation by default, so a real return of about 2.9%. Every figure is shown in today's money.
A worked example
Take someone who is 35, spends £30,000 a year, and retires at 67. Their full FIRE number is £30,000 ÷ 4% = £750,000. Discount that back 32 years at a 2.9% real return and the Coast FIRE number is about £299,000. Leave that £299,000 invested and it grows back to £750,000 by 67 — without adding another penny.
Which UK pots to include
Coast FIRE only works if you count the right money. Add up the pots that grow like investments. Treat guaranteed income, like the State Pension, as a reduction to your spending instead.
| Pot or account | Include? | Why |
|---|---|---|
| Workplace pension (DC) | Yes | Counts fully as part of your invested pot. |
| Stocks & shares ISA | Yes | Counts fully, and the growth is tax-free. |
| SIPP | Yes | A self-invested personal pension counts like any other pot. |
| Lifetime ISA | Yes | Counts, plus the 25% government bonus on what you pay in. |
| State Pension | As income | Don't add it to your pot. Subtract its yearly value from your spending. |
| Defined benefit / final salary | As income | Treat the guaranteed yearly amount as a cut to your spending. |
| Cash savings | No | Cash grows slower than investments, so including it overstates your number. |
| Your home | Depends | Only count it if you actually plan to sell and invest the proceeds. |
How the State Pension changes your number
The full new State Pension is £241.30 a week — about £12,550 a year (our estimate of £241.30 × 52; gov.uk only quotes the weekly figure). To get the full rate you need 35 qualifying National Insurance years, based on records from April 2016. It's a guaranteed income for life, so the smart move is to subtract it from your retirement spending rather than adding it to your pot.
Worked example
Say you want £30,000 a year and expect the full State Pension of about £12,550. Your investments only need to cover the remaining £17,450 a year. That drops your full FIRE number from £750,000 to about £436,000 — and your Coast FIRE number falls with it.
The State Pension starts at 67, not when you stop work, so you may still need savings to bridge the earlier years.
When can you actually access the money?
Hitting your Coast FIRE number is one thing. Being allowed to spend it is another. UK rules set different ages for each pot.
Pensions: age 55, rising to 57
You can normally take a workplace or private pension from 55. That minimum age (the NMPA) rises to 57 on 6 April 2028, so anyone born after April 1971 waits until 57.
State Pension: age 67
The State Pension age is currently 67. You can't draw it earlier, which is why your own pots have to carry the years before that.
ISAs: no age limit — your bridge
An ISA has no minimum withdrawal age. If you want to stop work before 57, a stocks & shares ISA is what bridges the gap until your pension unlocks.
Lifetime ISA: pay in to 50, withdraw at 60
You can pay into a LISA until 50 (first payment before 40) and earn the 25% bonus, but penalty-free retirement withdrawals only start at 60.
UK Coast FIRE number by age
Based on £30,000 a year of spending, the 4% rule, a 6% return with 3% inflation, and retiring at 67. All figures are in today's pounds.
| Current age | Years to 67 | Coast FIRE number | Full FIRE number |
|---|---|---|---|
| 25 | 42 | £224,584 | £750,000 |
| 30 | 37 | £259,252 | £750,000 |
| 35 | 32 | £299,271 | £750,000 |
| 40 | 27 | £345,468 | £750,000 |
| 45 | 22 | £398,796 | £750,000 |
| 50 | 17 | £460,357 | £750,000 |
These use £30,000 of spending. Change your own spending in the calculator above for your exact number.
Our numbers look bigger than some UK tools because they're in today's money — real purchasing power, not an inflated future figure.
Coast FIRE vs Barista FIRE in the UK
Coast FIRE means you stop saving for retirement and only earn enough to cover your living costs today — your pot grows on its own. Barista FIRE means working part-time to pay for part of your expenses. In the US, Barista FIRE is often about keeping a job for health insurance. In the UK the NHS removes that reason, so the choice is really about income, not cover.
Is Coast FIRE right for you? Read the honest pros and cons →Sources and methodology
UK figures are taken straight from gov.uk and checked for the current tax year.
- ISA allowance — £20,000 for 2026/27 (gov.uk)
- New State Pension — £241.30 a week (gov.uk)
- Normal minimum pension age — 55, rising to 57 in 2028 (gov.uk)
- Pension annual allowance — £60,000 (gov.uk)
- State Pension age — 67 (gov.uk)
Figures checked for the 2026/27 UK tax year · last reviewed June 2026.
Educational only — not financial advice. This is an illustrative projection; markets don't grow in a straight line. Nothing is stored — every calculation runs in your browser.
How to use this UK Coast FIRE calculator
Enter your age and what you've invested
Put in your current age and the total you've already invested — your workplace pension, ISA and SIPP added together. Leave out cash savings; they grow at a different rate.
Set your retirement spending
Enter how much you want to spend each year in retirement, in today's pounds. The default is £30,000. The calculator also assumes you retire at 67, the current State Pension age.
Read your number in pounds
Your Coast FIRE number appears straight away in £, with a status badge. It's how much you need invested today so you can stop adding money and still reach full retirement by 67.
Frequently Asked Questions
It depends on your spending and age. With £25,000–£30,000 of annual spending, your full FIRE target is £625,000–£750,000. Your Coast FIRE number is smaller because your pot still has years to grow — for a 35-year-old spending £30,000, it's about £299,000 in today's money. Use the calculator above for your own figure.
Yes for pots that grow like investments — your workplace DC pension, SIPP and ISA all count. Treat guaranteed income differently: subtract the State Pension and any defined benefit pension from your yearly spending instead of adding them to your pot.
The full new State Pension is £241.30 a week, roughly £12,550 a year, and you need 35 qualifying National Insurance years for the full rate. Subtract it from your spending. If you want £30,000 a year, your investments only need to cover about £17,450, which cuts your full FIRE number from £750,000 to around £436,000.
You can stop work, but you can't touch a workplace or private pension until 55 — rising to 57 from 6 April 2028. To retire earlier, use an ISA, which has no age limit, to bridge the years until your pension and State Pension (age 67) kick in.
A nominal return of 5–7% is a reasonable long-term assumption for a global stock portfolio. What matters is the real return after inflation. This calculator uses 6% growth with 3% inflation, giving about 2.9% real. Going above 8% is optimistic for planning.
No. With Coast FIRE you stop saving for retirement and only earn enough to cover today's costs. Barista FIRE means working part-time to pay for part of your expenses. Barista FIRE matters less in the UK than the US because the NHS means you don't need a job just for health cover.
No. Every calculation runs in your browser. Nothing you enter is sent to a server or saved anywhere, so your numbers stay private.
Want the basics first? Read our guide on what Coast FIRE is.
"It's not that I don't want to work hard—I just want to work hard for myself."
May you reach the shore soon 🌅