UK FIRE calculator
Plan retirement with assumptions you can inspect.
UK-focused FIRE projection in today's money. Includes ISA allowance, SIPP relief, state pension timing, and a simple post-tax income estimate.
These are projections, not guarantees or financial advice.
Your FIRE number
£875,000
Based on your target retirement income of £35,000 and a 4% withdrawal rate.
Projected retirement date
Age 66
Estimated calendar year 2062.
Monthly retirement income (today's money)
£1,913
Estimated post-tax income at target retirement age 55.
Income breakdown
State pension£0
Defined benefit£0
Investment withdrawals£23,379
Projected net worth trajectory£859,426
Age 30Target age 55Age 71
Current positionTarget age markerHover point
Age 55: £584,469
View trajectory data table
| Age | Projected net worth |
|---|---|
| 30 | £35,000 |
| 35 | £120,120 |
| 40 | £216,140 |
| 45 | £324,455 |
| 50 | £446,640 |
| 55 | £584,469 |
| 60 | £659,309 |
| 65 | £743,731 |
| 70 | £838,964 |
| 71 | £859,426 |
Gap analysis
- Increase monthly savings by about £1,024. (~24.6% of current household salary)
- Prioritise tax-efficient contributions: currently £400/month goes to workplace pensions. Check if your employer offers additional matching above current levels.
- Keep contributions unchanged and retire around age 66 (11 years later).
- Keep target age 55 and lower retirement income target by about £12,046 to £22,954 per year.
A 1% return swing changes retirement timing by about 6 years.
How this model works
- Your target retirement income is user-set and shown in today's money.
- Personal monthly savings are split between ISA and personal pension using your ISA share.
- Workplace pension pot and employee/employer monthly contributions are modeled separately.
- State pension timing and simple UK tax assumptions are applied to estimate post-tax income.
Assumptions and guardrails
- Figures are shown in today's money using your inflation assumption.
- Workplace pension employee and employer contributions are modeled separately.
- Pension withdrawals are treated as taxable income by default.
- Pension tax is simplified and does not replace personal tax advice.
- State Pension is estimated from current UK legislation and may change.
- ISA allowance assumed at £20,000 per person per tax year.
- SIPP contribution uplift uses current marginal tax band assumptions.