🔥 FIRE Calculator
FIRE (Financial Independence, Retire Early) projects your path to financial independence. The calculator auto-populates from your real spending and investment data, persists your scenario inputs across sessions, and models UK-specific rules including State Pension and private pensions.
What you’ll see
- FIRE Number — Target portfolio size based on annual expenses ÷ safe withdrawal rate
- Progress bar — How much of your FIRE number you’ve already accumulated
- Portfolio Projection chart — Line chart showing portfolio growth vs. FIRE target over time
- Years to FIRE — Estimated year you’ll reach financial independence
- Sensitivity widget — “What if I contribute more?” comparison at +£100, +£200, +£500/month
- State Pension panel — Estimates your UK State Pension based on NI qualifying years
- Private pension panel — Lists your SIPP accounts with employer contributions and unlock age
FIRE Variants
Switch between three modes using the tabs at the top:
| Tab | Description |
|---|---|
| Lean FIRE | Lower-cost lifestyle target (typically £15,000–20,000/yr) |
| Standard FIRE | Your actual expense level — the default |
| Coast FIRE | Lump sum needed now so you can stop contributing and still reach FIRE by your target age |
Coast FIRE formula: Coast Number = FIRE Number ÷ (1 + annual return)^years to target
Coast FIRE mode shows the Coast Number in place of the progress bar.
Scenario Inputs
All inputs are saved automatically and persist across reloads and devices.
| Input | What it means |
|---|---|
| Annual Expenses | Your expected annual spending in retirement. Auto-populated from your last 3 months of transactions. |
| Safe Withdrawal Rate | Percentage of portfolio withdrawn per year in retirement. Default: 4% (the “4% rule”). |
| Expected Return | Annual investment growth rate. Default pulled from your profile. |
| Monthly Contributions | What you add to investments each month. Auto-populated from categorised savings transactions. |
| Target Retirement Age | The age you want to reach FIRE. |
Auto-population from transactions
On first load (or when no saved value exists), expenses and contributions are estimated from the last 3 months of your categorised transactions:
- Expenses — Average monthly spend, excluding savings and income categories
- Contributions — Average monthly savings/investment transfers
You can override either value — your override is saved immediately.
State Pension
The UK State Pension is modelled accurately using your National Insurance qualifying years.
- Full State Pension (2024/25): £11,502/year — requires 35 qualifying years
- Minimum: 10 qualifying years
- Pro-rata formula:
State Pension = min(NI years, 35) ÷ 35 × £11,502
From age 67 onwards, the State Pension amount is added to your annual income in the projection, reducing the drawdown required from your portfolio.
Enable or disable with the Include State Pension toggle. Enter your NI qualifying years — you can check your record at gov.uk/check-national-insurance-record .
Private Pensions
If you have any SIPP (Self-Invested Personal Pension) accounts in your Investments, a Private Pensions panel appears on the FIRE page showing:
- Account name and current value
- Employer contribution (monthly £ — editable per account in Investments)
- Pension unlock age (default: 57, rising from 55 to 57 in 2028)
- DC vs DB type
Defined Contribution (DC): Grows based on contributions + investment returns. The projected value feeds into your FIRE portfolio total.
Defined Benefit (DB): Pays a fixed annual income regardless of markets. The DB annual income reduces the drawdown required from your portfolio (similar to State Pension).
Employer contributions from all SIPP accounts are automatically included in the monthly contributions fed into the projection.
Portfolio Projection Chart
The area chart shows:
- Portfolio value (filled area) — projected growth year by year
- FIRE Number (dashed line) — your target
- Crossover point annotated with a label
- Pension unlock age shown as a vertical reference line
Hover over the chart to see: age, total portfolio value, and percentage progress towards FIRE.
The year-by-year projection table below the chart provides the full detail.
Sensitivity Widget
Below the main stats, the “What if I contribute more?” widget shows how much earlier you’d reach FIRE if you increased monthly contributions by:
- +£100/month
- +£200/month
- +£500/month
All figures use the same expected return and expenses as your main scenario.
Tips
- Use the 4% rule as a starting point: FIRE Number = Annual Expenses × 25
- Check your NI qualifying years at gov.uk and enter them for an accurate State Pension estimate
- Add employer pension contributions to your SIPP accounts in Investments — they’re included in projections automatically
- Lean FIRE can be a useful intermediate goal: reaching it gives optionality even if you want more later
- Coast FIRE is useful if you’re already investing well — it shows you may be able to reduce contributions sooner than you think