FIRE Calculator

Category: Retirement

- October 31, 2025

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Calculate when you can achieve Financial Independence and Retire Early based on your savings rate, expenses, and investment returns.

Current Financial Status

Current Age:

years

Current Savings:

Income & Expenses

Annual Income (after tax):

Annual Expenses:

Savings Rate:

Annual Savings:

Investment Parameters

Expected Annual Return:

Safe Withdrawal Rate:

Expected Inflation Rate:

FIRE Target Amount:

Advanced Options

Post-Retirement Income:

Expected Tax Rate in Retirement:

Adjust expenses for inflation

Show calculation details

FIRE Projection Results

Years to FIRE

years

Retirement Age

years old

FIRE Date

Final Portfolio

£0

at retirement

Annual Withdrawal

£0

in retirement

Monthly Income

£0

in retirement

Portfolio Growth Projection

Calculation Details

Year	Age	Annual Contribution	Investment Returns	Portfolio Value	Target Value

FIRE Calculation Method

Your FIRE number represents the amount needed to support your retirement expenses using the 4% rule (or your selected withdrawal rate). The formula used:

FIRE Number = Annual Expenses ÷ Withdrawal Rate

For your inputs: £40,000 ÷ 4% = £1,000,000

About FIRE (Financial Independence, Retire Early)

FIRE is a financial movement focused on extreme savings and investment to enable early retirement. The core principles involve saving a significant portion of your income (often 50-70%) and investing it to build a portfolio that can sustain your expenses indefinitely.

Key FIRE Concepts

The 4% Rule: A commonly used guideline suggesting that you can safely withdraw 4% of your portfolio value annually in retirement without depleting your savings.
Savings Rate: The percentage of your income that you save. This is the most important factor in determining how quickly you can achieve FIRE.
FIRE Number: The amount of money you need to have invested to support your lifestyle indefinitely, typically calculated as 25 times your annual expenses (for a 4% withdrawal rate).
Financial Independence: The point where your passive income from investments exceeds your expenses, making paid work optional.

FIRE Variations

Traditional FIRE: Focused on accumulating 25-30 times your annual expenses before retiring.
Lean FIRE: Retirement on a minimal budget, often under £40,000 per year for a household.
Fat FIRE: Retirement with a more generous budget, typically over £100,000 per year.
Barista FIRE: Semi-retirement where you work part-time to cover some expenses while your investments grow.
Coast FIRE: Having enough invested that you only need to cover your current expenses, without adding more to your retirement accounts.

Understanding the FIRE Calculator

The FIRE Calculator is a handy tool for anyone wanting to achieve Financial Independence and Retire Early (FIRE). It helps you determine when you can retire based on your financial situation. By entering your current age, savings, income, expenses, and Investment returns, you can see how close you are to your goals. This tool makes planning for your future easier and more straightforward.

Inputting Your Financial Details

To get the best results, you’ll need to fill in some key financial details. Start with your current age and savings. Next, enter your annual income and expenses. These figures help calculate your savings rate, which shows how much of your income you save. The calculator will then use these inputs to project when you'll be able to retire.

Understanding Savings Rate and Contributions

Your savings rate is crucial for reaching FIRE. This percentage shows how much of your income you save each year. In the calculator, it’s automatically calculated based on your income and expenses. Additionally, the calculator also estimates your annual savings, giving you a clear view of how much you’re contributing towards your Retirement goals.

Investment Parameters Matter

The FIRE Calculator allows you to input various investment parameters. Key fields include the expected annual return on your investments, the safe withdrawal rate, and inflation expectations. Each factor affects how much you’ll need to save and how quickly your investments will grow. Optimising these figures helps you create a realistic plan for early retirement.

Exploring Advanced Options

The calculator offers advanced options for those who want to dive deeper into their financial plans. You can add any expected income you might have post-retirement, such as part-time work. There’s also space to input your expected tax rate during retirement, which could impact how much you can withdraw annually. These options allow for a more tailored calculation.

What Results Can You Expect?

Years to FIRE: Discover how many years you need to save to reach your retirement goal.
Retirement Age: Find out at what age you’ll be able to retire comfortably.
FIRE Date: Get an estimate of the date you can officially retire.
Final Portfolio: See the projected value of your investment portfolio at retirement.

Understanding Your FIRE Number

Your FIRE number is the amount you need to retire comfortably. The calculator uses a formula to help you find this number based on your annual expenses and the withdrawal rate you choose. Knowing this figure is vital, as it gives you a clear target to aim for in your savings journey. The calculator simplifies the guessing and gives you clarity on how much you'll need.

Exploring Financial Independence Concepts

The calculator also introduces you to key concepts within the FIRE movement. You'll learn about the 4% rule, which suggests you can withdraw 4% of your portfolio each year without running out of money. You’ll also understand the importance of saving a high percentage of your income to reach financial independence. Familiarising yourself with these concepts is essential for effective planning.