FIRE number, years to FI, and safe withdrawal rate calculator
FIRE Number & Financial Independence Calculator
What is FIRE?
FIRE (Financial Independence, Retire Early) is a lifestyle movement where you save aggressively to accumulate a portfolio large enough to live off investment returns indefinitely. The 4% rule (from the Trinity Study) suggests you can safely withdraw 4% annually from a diversified portfolio.
UK FIRE Strategies
ISA: Tax-free growth and withdrawals — ideal for early retirement (accessible before 57)
SIPP/pension: Tax relief on contributions but locked until age 57 (from 2028). Perfect for bridging to State Pension Age
GIA: General Investment Account for additional savings beyond ISA/pension limits
State Pension: From age 66, reduces your portfolio withdrawal needs significantly
Frequently Asked Questions
What is the FIRE number?
Your FIRE number is the investment portfolio size needed to sustain your annual expenses indefinitely. Formula: Annual Expenses ÷ Safe Withdrawal Rate. At 4% SWR, 25× your annual expenses.
What is the 4% safe withdrawal rate?
Based on the Trinity Study (1998), a 4% annual withdrawal from a diversified portfolio (60% equities, 40% bonds) has historically lasted 30+ years in the US. UK investors may use 3.5% for more conservatism.
Is the 4% rule safe for UK FIRE?
UK equity market has underperformed US historically. Many UK FIRE advocates use 3–3.5% SWR and hold globally diversified portfolios (e.g., FTSE All-World) to reduce UK concentration risk.
How does the UK State Pension help FIRE?
The full new State Pension (£11,502/yr in 2026/27) significantly reduces your FIRE number. If you can survive to 66 on a smaller portfolio, you then have State Pension bridging much of your income need.
What is Lean FIRE vs Fat FIRE?
Lean FIRE: FI with minimal spending (£20,000/yr or less). Fat FIRE: FI with comfortable/luxurious spending (£50,000+/yr). Barista FIRE: partially retired with some part-time income to supplement a smaller portfolio.
Can I access my pension before 57 for FIRE?
From 2028, the minimum pension access age rises to 57 (from 55). ISAs have no minimum age restriction — withdrawals are always tax-free. Most UK FIRE plans use ISAs for early retirement years, with SIPPs bridging from 57/58.
What assets count towards the FIRE number?
Investment accounts (ISAs, SIPPs, GIAs), property equity if downsizing, and any recurring income that reduces withdrawal needs. Do NOT include your primary home unless you plan to sell and rent.
How do UK taxes affect FIRE withdrawals?
ISA withdrawals are tax-free. SIPP drawdown: 25% PCLS tax-free, remainder taxed as income. GIA: CGT on gains above £3,000 annual exempt amount. Dividend income above £500 taxable. Smart sequencing of account types minimises tax.
What return should I assume for FIRE calculations?
Real (inflation-adjusted) returns: UK equities ~4.5% p.a. long-term, global equities ~5–6%. Bonds ~1–2% real. A diversified portfolio of 80% equities, 20% bonds: ~4–5% real. Use conservative assumptions (4–5%) for planning.
What is the FIRE portfolio sequence risk?
Retiring into a market downturn (early in retirement) is the biggest risk. Strategies: keep 1–2 years' cash, use bucket strategy, maintain some flexibility to reduce spending or earn part-time income in bad years.
How do I calculate how many years to FIRE?
Use the compound growth formula or our calculator. Fewer inputs: Current portfolio × growth rate + annual savings → years until portfolio reaches FIRE number. Most UK FIRE achievers save 40–60% of income.
Should I include property in my FIRE number?
Only if you will access the equity (sell and downsize, or rent). Your primary residence provides housing but not income in standard FIRE analysis. Rental property income CAN reduce your portfolio withdrawal needs.