FIRE Calculator
Calculate your path to Financial Independence and Early Retirement with the 4% rule.
FIRE Number Needed
£750k
Annual Savings
£10,000
Savings Rate
25.0%
Years to FIRE
25
FIRE Age
55
Passive Income at FIRE
£30,000/year
Your FIRE Path
Save £10,000/year (25.0% of income) to reach financial independence in 25 years at age 55.
Portfolio Growth to FIRE
Assumes 7% annual return. Actual returns vary. Not financial advice.
Get AI-Powered Insights
Personalized tips to optimize your finances
Share Your Results
Recommended Next Steps
Trusted partnersBest-selling personal finance & investing books. Start your money journey.
Physical calculators & planning tools for your finances.
Shop millions of products with fast delivery.
#ad · We may earn a commission via these links, at no extra cost to you.
FIRE Movement Essentials
Handpicked tools to help you succeed
The Psychology of Money
The Simple Path to Wealth
Playing with FIRE
Your Money or Your Life
FIRE Calculator Spreadsheet
#ad · As an Amazon Associate we earn from qualifying purchases at no extra cost to you.
Your Path to Financial Independence
Learn the FIRE movement principles, calculate your independence number, and discover strategies to retire early.
What Is FIRE (Financial Independence, Retire Early)?
FIRE is a savings strategy focused on building enough invested wealth that passive investment income covers your living costs, freeing you to stop working for money well before the traditional retirement age. Your FIRE number is the portfolio size needed to sustain your annual spending indefinitely using a safe withdrawal rate.
The calculator above uses the standard formula: FIRE number = annual expenses ÷ withdrawal rate. At a 4% withdrawal rate, this is the same as multiplying your annual expenses by 25.
Savings Rate Determines Your Timeline
| Savings Rate | Approx. Years to FIRE |
|---|---|
| 15% | ~43 years |
| 25% | ~32 years |
| 40% | ~22 years |
| 55% | ~14 years |
| 65%+ | ~10 years |
Estimates assume a 5% real (after-inflation) investment return and a 4% withdrawal rate. Your actual timeline will vary with market performance.
The Different Flavours of FIRE
Lean FIRE
Retiring on a minimal budget, often under £25k/year, prioritising early freedom over lifestyle spending.
Fat FIRE
A larger portfolio supporting a comfortable or even luxurious lifestyle, requiring higher income and savings rates.
Coast FIRE
Saving aggressively early, then letting compounding do the work while working a lower-stress job that just covers expenses.
Risks to Consider
The 4% rule was developed from historical US market data and isn't guaranteed to hold in every future scenario, sequence-of-returns risk (poor market performance in your first few retirement years) is the biggest threat to any FIRE plan. Many people build in a buffer by targeting a slightly lower withdrawal rate (3–3.5%) or keeping some cash reserves to avoid selling investments during a downturn.
⚠️ Important Disclaimer
This calculator provides illustrative projections only, based on constant assumed returns, real markets are volatile and returns are never guaranteed. It is not financial advice. Always consult a qualified, FCA-regulated financial adviser before making investment or early-retirement decisions.
Worked Example: Spending £30,000 a Year
Under the 4% rule your target is 25 times annual spending, so £30,000 a year needs about £750,000. If you already have £150,000 and save £1,500 a month, assuming a 5% return above inflation, you would reach the target in roughly 16 years.
Cutting spending to £24,000 lowers the target to £600,000 and also frees up money to save, which shortens the journey twice over. That is why spending matters more than income in FIRE planning.
Frequently Asked Questions
Is the 4% rule guaranteed?
No. It is based on historical data. People retiring early often use a lower rate such as 3.5% for extra safety.
What about the gap before I can access my pension?
If you retire before pension age you will need accessible savings, such as ISAs, to bridge the gap. Check the current minimum pension age.
Does FIRE account for inflation?
Using a real return, which is the return after inflation, keeps the figures in today's money.
Frequently Asked Questions
What is the 4% rule?
The 4% rule suggests you can withdraw 4% of your portfolio annually in retirement with high probability it will last 30+ years. Some use 3% or 3.5% for more safety.
What is FI?
Financial Independence means your investments generate enough passive income to cover living expenses, giving you freedom to work by choice, not necessity.
How much do I need for FIRE?
Multiply your annual expenses by 25 (for 4% withdrawal rate). E.g., £30k/year expenses = £750k portfolio needed.
What savings rate do I need?
To retire in 10 years: ~65% savings rate. 20 years: ~40%. 30 years: ~25%. Higher savings rates dramatically accelerate FIRE.
Key Terms Explained
Plain-English definitions of the financial terms used in this calculator.
- Compound Interest
- Interest earned on both your original money and on interest already added. Over long periods compounding accelerates growth dramatically, the earlier you start saving or investing, the more it works in your favour.
- Inflation
- The rate at which prices rise over time, eroding the buying power of money. If inflation is 3%, £100 today buys only about £97 worth of goods next year, which is why long-term savings need to beat inflation.
- Pension Contribution
- Money paid into a pension by you and your employer. Contributions get tax relief at your marginal rate, and under auto-enrolment a minimum of 8% of qualifying earnings goes in (at least 3% from your employer).
- FIRE (Financial Independence, Retire Early)
- A movement based on saving aggressively and investing until your portfolio covers living costs, commonly estimated as 25× annual expenses, based on the 4% safe withdrawal rate.
Be first to know when we launch new tools
Join 2,400+ UK readers who get early access to new calculators, expert financial guides, and free resources, straight to their inbox.
- First to hear about new calculators
- Exclusive money-saving tips
- Free UK Tax Cheatsheet 2026/27
Not Financial Advice: This calculator is for informational and educational purposes only. Results are estimates and do not constitute financial advice, recommendations, or regulated advice. We are not authorised or regulated by the Financial Conduct Authority (FCA). Always consult a qualified financial adviser for personalised advice. Tax treatment depends on your individual circumstances and may change. Tax laws and rates may change. Past performance does not guarantee future results.
