CoastCalc
Fat FIRE Calculator

Fat FIRE Calculator

Retire early and live luxuriously. Fat FIRE is financial independence with a generous, unconstrained lifestyle — typically £80,000+ per year.

Your Details

30
1870
65
3580
£50,000
£0£1,000,000
£10,000
£0per year£80,000
7%
2%~7% historical avg15%
£100,000
£10,000£300,000
3.5%
2%Luxury lifestyle, 3-4%7%

Fat FIRE Number

£2,857,143

At 3.5% withdrawal

Years to FIRE

41 yrs

FIRE age: 71

Coast FIRE Number

£267,608

Invested today to coast

Annual Contribution

£10,000

Needed to hit target

Portfolio Projection

Assumes 7% nominal annual return. Not inflation-adjusted.

What is Fat FIRE?

Fat FIRE is financial independence at a high standard of living — business class flights, premium healthcare, private schools, regular holidays, and no financial constraints. It typically requires an annual budget of £80,000 to £200,000 or more, meaning a portfolio of £2m–£5m+.

Fat FIRE practitioners often use a lower withdrawal rate (3–3.5%) for extra safety, because the stakes are higher — both in terms of portfolio size and lifestyle expectations. A market crash in early retirement is much more damaging when you're withdrawing £120,000/year than £20,000.

Fat FIRE vs other FIRE variants

VariantAnnual IncomePortfolio NeededLifestyle
Lean FIRE£15k–£25k£375k–£625kFrugal
FIRE£25k–£50k£625k–£1.25mComfortable
Fat FIRE£80k–£200k+£2m–£5m+Luxurious
Barista FIREAnyReduced by PT incomeSemi-retired

Worked example

Scenario: High earner, age 38, targeting £120,000/year in retirement. Using 3.5% SWR for a luxurious 45-year retirement.

Fat FIRE number: £120,000 ÷ 3.5% = £3,428,571

Current portfolio: £350,000 (pension + ISA + investments). Saving £5,000/month.

Time to Fat FIRE: At 7% real return, approximately 18 years — reaching Fat FIRE around age 56.

Frequently asked questions

How much do I need for Fat FIRE in the UK?

At £80,000/year with a 3.5% withdrawal rate, you need £2,285,714. At £120,000/year, you need £3.43 million. At £200,000/year, £5.71 million. These are pre-tax figures — ISA withdrawals are tax-free, but pension drawdown and investment account gains may be taxable, so gross up accordingly.

What is the best investment strategy for Fat FIRE?

Most Fat FIRE wealth is built through high income combined with aggressive saving into low-cost global index funds in ISAs and pensions. The Stocks and Shares ISA (£20,000/year allowance) and Self-Invested Personal Pension (SIPP) are the primary vehicles. At high income levels, carry-forward pension contributions can accelerate accumulation significantly.

How do I manage tax in Fat FIRE withdrawals?

Efficient drawdown involves sequencing: use ISA first (tax-free), then draw from taxable accounts using the capital gains annual exemption, and finally pension income managed to stay within the basic or higher rate tax band. At £80,000–£120,000/year, careful sequencing can reduce effective tax rates considerably.

Should I use a 3% or 4% withdrawal rate for Fat FIRE?

Fat FIRE practitioners often prefer 3–3.5% because the portfolio is large, the lifestyle expensive, and the consequences of running out are severe. At £3.5 million, a 3% withdrawal is £105,000/year versus £140,000/year at 4%. Many Fat FIRE retirees prefer the additional security margin over the extra income.

What are the biggest Fat FIRE risks in the UK?

Pension Lifetime Allowance considerations (abolished in 2024, but worth reviewing with an IFA), inheritance tax planning on large estates, sequencing risk in the early retirement years, and the psychological challenge of transitioning from high-achievement careers to retirement. Lifestyle inflation is also a risk — Fat FIRE requires discipline to avoid target creep.