Coast FIRE Calculator UK
Free Coast FIRE Calculator UK. Calculate your Coast FIRE number with country-specific defaults, formulas, worked examples, and FAQs.
Your Numbers
Coast FIRE Achieved!
$71,432
is your Coast FIRE number. You already have enough!
Progress 119%
FIRE Nest Egg
$1,375,000
at retirement age
Coast Age
25
Already coasting!
Cash Freed
$12,000
per year from saving
Real Return
5.37%
after inflation
Growth Projection
Coast (no more saving) Keep saving Target nest egg
How to Use the Coast FIRE Calculator UK
To use the Coast FIRE calculator in the UK, enter your age, the age you want to retire, the yearly income your pension and ISA must provide, and the value of your investments today. The result is your Coast FIRE number: the amount you need invested now so your pots can grow to a full retirement fund without another pound of saving.
- Enter your Current Age.
- Set your Retirement Age. Two UK ages matter. State Pension age is 66 and is rising to 67 between 2026 and 2028. The earliest age you can draw a private or workplace pension is 55, rising to 57 from 6 April 2028.
- Enter Annual Spending in Retirement in pounds, at today's prices. Subtract the State Pension you expect. The full new State Pension is roughly £12,500 a year for 2026/27, but your amount depends on your National Insurance record. Check your forecast on GOV.UK.
- Enter Current Invested Assets. Add your workplace pension, SIPP, Stocks and Shares ISA, Lifetime ISA, and general investment account. Leave out Cash ISAs and premium bonds if you won't invest them.
- Enter your Monthly contribution. Include your own pension contributions, your employer's contribution, tax relief, and ISA deposits.
- Check Advanced Settings. Many UK planners use a lower safe withdrawal rate (SWR) than the US default, often 3% to 3.5%, since historical UK-only portfolios have supported lower withdrawals.
How to read your results
- Coast FIRE number is the amount you need invested today.
- Progress compares what you have now to that number.
- FIRE Nest Egg is the full pot you need at retirement, in today's pounds.
- Coast Age is when your pots reach the coast line, assuming your monthly contribution continues until then.
- Cash Freed is the yearly saving you can stop once you coast.
- Real Return is your expected growth after inflation.
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How the Coast FIRE Calculator UK Works
The Coast FIRE calculator UK finds the full pension pot your spending needs, then works out how much smaller that pot can be today if it compounds untouched until retirement.
The formula
FIRE Nest Egg = Annual Spending ÷ Safe Withdrawal Rate
Real Return (r) = (1 + Growth Rate) ÷ (1 + Inflation Rate) − 1
Coast FIRE Number = FIRE Nest Egg ÷ (1 + r)^Years| Variable | Meaning | Unit |
|---|---|---|
| Annual Spending | Yearly spending your pots cover, after State Pension | £, today's prices |
| Safe Withdrawal Rate | First-year withdrawal as a share of the pot | % |
| Growth Rate | Average yearly return before inflation | % per year |
| Inflation Rate | Average yearly rise in CPI | % per year |
| Years | Retirement Age − Current Age | years |
Worked example
James is 35 and plans to stop work at his State Pension age of 67. He wants £32,000 a year and expects about £12,000 from the State Pension, so his investments must provide £20,000. He uses a 3.5% SWR, 6.5% growth from a global index fund, and 2.5% inflation.
- FIRE Nest Egg: £20,000 ÷ 0.035 = £571,429
- Real Return: 1.065 ÷ 1.025 − 1 = 3.90%
- Growth factor over 32 years: 3.404
- Coast FIRE number: £571,429 ÷ 3.404 = £167,857
Factors that change your result
- Tax. Pension withdrawals are taxed as income after the 25% tax-free portion. ISA withdrawals are tax-free. Enter gross spending if most of your money sits in pensions.
- Two access dates. Pension money is locked until 57 (from April 2028), and the State Pension starts at 66 to 67. Retiring earlier needs ISA money to bridge the gap.
- Fees. Platform and fund charges reduce growth. Subtract them from the growth rate.
- Inflation. The Bank of England targets 2% CPI inflation, but UK inflation passed 10% in 2022. A 2.5% to 3% assumption gives a buffer.
- Rounding. Results are rounded to whole pounds, contributions are added yearly, and Coast Age is shown in whole years.
Coast FIRE Calculator UK FAQs
Should I include the State Pension in my Coast FIRE number?
Yes, subtract your expected State Pension from your spending before you enter it. The State Pension rises each year under the triple lock and covers a large share of a modest retirement budget. Removing £12,000 from the spending input cuts the pot you need by £342,857 at a 3.5% SWR.
What safe withdrawal rate should UK investors use?
Most UK FIRE planners use 3% to 3.5%. The 4% rule comes from US market history, and studies of UK-only portfolios point to lower sustainable rates. A globally diversified portfolio supports a figure closer to 4%, so test both.
Can I count my workplace pension towards Coast FIRE?
Yes, workplace pensions and SIPPs count toward your Coast FIRE number. Pension money gets tax relief going in and grows tax-free, which makes it one of the strongest compounding accounts in the UK. Remember you can't touch it before the minimum pension age.
Can I coast FIRE before my pension access age?
Yes, coasting only means you stop saving, not that you stop working. You still earn enough to cover today's bills. Stopping work fully before 57 requires accessible money, such as ISAs, to pay for the years before pension access.
Is the Coast FIRE calculator UK accurate?
The maths is exact, but the result depends on your assumptions about returns, inflation, and tax. Small changes matter: dropping growth from 6.5% to 5.5% raises James's Coast FIRE number by about a third. Re-run the numbers each tax year.
Does the calculator account for UK tax?
No, the calculator does not apply UK income tax. Enter spending as the gross amount you'll withdraw, or keep more money in ISAs, where withdrawals are tax-free.