FIRE Calculator — Find Your Financial Independence Number
Calculate your FIRE number, see how close you are, and find out how many years until you can retire early — using the 2026-updated safe withdrawal rate.
FIRE in 2026 — What's Changed
FIRE — Financial Independence, Retire Early — means saving and investing aggressively enough that investment returns alone can fund your lifestyle, often decades before traditional retirement age. The core idea hasn't changed in years. What has changed in 2026 is the safe withdrawal rate (SWR) most experts recommend using.
The famous "4% Rule" comes from the 1998 Trinity Study, building on the 1994 Bengen study, which found that historically, a 4% withdrawal rate (adjusted for inflation each year) had a high success rate over 30-year retirement periods for a 60/40 equity-bond portfolio. For 2026, Morningstar revised its recommended safe withdrawal rate to 3.9%, down slightly from previous years, based on updated inflation and future return assumptions — giving a 90% probability of funds lasting 30 years.
| Safe Withdrawal Rate | Multiplier (1 ÷ SWR) | FIRE Number on £30k/yr spending | Note |
|---|---|---|---|
| 5% | 20× | £600,000 | Aggressive — higher failure risk historically |
| 4% | 25× | £750,000 | Classic Trinity Study figure |
| 3.9% | 25.6× | £769,000 | Morningstar's 2026 update |
| 3.5% | 28.6× | £857,000 | Conservative — common for early UK retirees |
| 3% | 33× | £990,000 | Very conservative — 33% more capital than 4% |
Using 3% instead of 4% requires roughly 33% more capital — often translating to 5 or more extra years of working and saving. There's no single "correct" rate; it's a trade-off between how much certainty you want and how long you're willing to keep working to get there.
Lean FIRE, Regular FIRE, and Fat FIRE
Not all FIRE looks the same. The amount you need depends entirely on the lifestyle you want to fund:
| FIRE Type | Annual Spending (UK, single) | FIRE Number (4% rule) | Lifestyle |
|---|---|---|---|
| Lean FIRE | ~£20,000 | £500,000 | Essentials only, minimal extras |
| Regular FIRE | £30,000 – £40,000 | £750,000 – £1,000,000 | Moderate, comfortable lifestyle |
| Fat FIRE | £60,000+ | £1,500,000+ | High spending, no real compromises |
The UK Pension and Lifetime Savings Association's Retirement Living Standards for 2026 estimate a "moderate" single retirement needs around £31,300/year and a "comfortable" one around £43,100/year — useful real-world benchmarks for the Regular and Fat FIRE figures above.
The State Pension Adjustment (UK-Specific)
If you're in the UK and planning FIRE, the State Pension matters more than many calculators account for. The full new State Pension is worth roughly £11,973/year currently, payable from age 67 (rising further in future). This income arrives regardless of your portfolio's performance, which means your portfolio only needs to cover the gap between your spending and your State Pension once you're past 67 — not your full spending forever.
For someone targeting £30,000/year in retirement, factoring in the full State Pension from 67 can reduce the equivalent capital needed by roughly £290,000-300,000 (at a 4% SWR) — since £12,000 of that £30,000 is effectively covered by the State Pension once it kicks in. The earlier years before State Pension age — the "bridge years" — need full portfolio coverage, which is why many UK FIRE plans use ISAs specifically for this gap (since pensions lock until 55, rising to 57 from 2028).
Getting There Faster — Why Savings Rate Matters More Than Returns
A common misconception is that FIRE requires extraordinary investment returns. It doesn't — it requires an extraordinarily high savings rate. Someone saving 50%+ of their income reaches FIRE dramatically faster than someone saving 10-15%, almost regardless of investment performance, simply because of the maths: a higher savings rate means both more money invested and less annual spending to fund in retirement — moving both sides of the equation simultaneously.
| Savings Rate | Approx. Years to FIRE (7% returns) |
|---|---|
| 10% | ~51 years |
| 25% | ~32 years |
| 50% | ~17 years |
| 65% | ~10.5 years |
| 75% | ~7 years |
Frequently Asked Questions
What is the 4% rule and is it still valid in 2026?
The 4% rule states that withdrawing 4% of your portfolio in year one of retirement, then adjusting that amount upward for inflation each subsequent year, had a high historical success rate over 30-year periods. It remains a widely used starting point in 2026, though Morningstar's updated research suggests 3.9% as a more conservative figure given current inflation and return assumptions, and some UK FIRE planners use 3.5% for longer retirement horizons.
How is my FIRE number calculated?
Your FIRE number equals your annual spending divided by your chosen safe withdrawal rate. Using the 4% rule, this is the same as multiplying annual spending by 25. For example, £30,000 in annual spending divided by 4% equals a £750,000 FIRE number. Using a more conservative 3.5% rate, the same spending requires roughly £857,000.
What is the difference between Lean, Regular, and Fat FIRE?
Lean FIRE covers essential spending only, roughly £20,000/year for a single person in the UK, requiring around £500,000 at a 4% SWR. Regular FIRE supports a moderate, comfortable lifestyle at £30,000-£40,000/year, requiring £750,000-£1,000,000. Fat FIRE targets higher spending of £60,000+/year with no real lifestyle compromises, requiring £1,500,000 or more.
Does the State Pension reduce how much I need to save for FIRE in the UK?
Yes, for the years after State Pension age (currently 67). The full new State Pension is worth roughly £11,973/year and arrives regardless of your portfolio's performance, meaning your invested portfolio only needs to cover the gap between your spending and the State Pension from that age onward — not your full spending indefinitely. Many UK FIRE plans use this to reduce their target FIRE number, while still saving enough in accessible accounts like ISAs to cover the bridge years before State Pension and pension access age.
Is FIRE realistic on an average income?
It requires a high savings rate, typically 50% or more of income, which is genuinely difficult on lower incomes after essential costs. However, FIRE isn't strictly all-or-nothing — many people pursue "Coast FIRE" (saving aggressively early, then easing off once compounding can finish the job alone) or simply use FIRE principles to retire a few years earlier than traditional retirement age, even without reaching full financial independence in their 30s.
What is sequence of returns risk and why does it matter for FIRE?
It's the risk that a market downturn occurring early in your retirement withdrawal period can derail an otherwise sound plan, even if long-term average returns are fine — because you're withdrawing from a shrunken portfolio during the recovery period. This is mitigated with cash reserves covering 1-3 years of expenses, a slightly lower withdrawal rate than the maximum theoretically sustainable, and flexibility to reduce spending during market downturns rather than withdrawing a fixed amount regardless of performance.