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How does this FIRE Calculator work?

This FIRE (Financial Independence, Retire Early) Calculator helps estimate how much wealth you need to achieve financial independence.

Unlike many simple FIRE calculators, this version considers much more than your current savings and expected investment return. It also includes different life stages, future income streams and multiple asset classes, providing a far more realistic long-term financial projection.

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Step 1 – Personal information

Enter your basic personal details:

  • Current age

  • Life expectancy

  • Target FIRE age

  • Preferred currency

  • Scenario name

These values form the foundation of all calculations.

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Step 2 – Asset classes

Different investments have different expected returns and risks.

You can select asset classes such as:

  • Stocks

  • ETFs

  • Bonds

  • Cryptocurrency

  • Residential real estate

  • Commercial real estate

  • Holiday property

  • Other investments

Each asset class can later receive its own assumptions.

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Step 3 – Current portfolio

For every asset class you enter:

  • Current value

  • Monthly contribution

The calculator automatically determines:

  • Total portfolio value

  • Total monthly contribution

  • Annual contributions

  • Portfolio allocation

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Step 4 – Returns, costs and risk

Each asset class can have its own:

  • Expected gross return

  • Annual costs

  • Risk level

The calculator then calculates the weighted expected return of your complete portfolio.

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Step 5 – Expenses

Spending usually changes throughout life.

You can therefore create multiple life stages, each with its own:

  • Start age

  • End age

  • Annual spending

You can also specify expected inflation and an additional safety margin.

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Step 6 – Future income

Many people continue to receive income after reaching FIRE.

Examples include:

  • State pension

  • Employer pension

  • Barista FIRE income

  • Rental income

  • Dividend income

  • Other passive income

Each income source includes:

  • Name

  • Start age

  • End age

  • Annual amount

The calculator only requires your investment portfolio to fund years in which expenses exceed other income.

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Step 7 – Simulation

The calculator supports multiple scenarios:

  • Conservative

  • Base case

  • Optimistic

You can also configure:

  • Monte Carlo simulations

  • Annual contribution growth

  • Stop contributions after FIRE

  • Annual portfolio rebalancing

Rather than calculating only a single outcome, Monte Carlo simulations generate hundreds or thousands of different market paths to evaluate the robustness of your plan.

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Step 8 – Results

After the calculation you will see:

  • Expected FIRE age

  • Wealth at your target FIRE age

  • Required bridge capital

  • Monte Carlo success rate

  • Median ending wealth

  • The age at which future income permanently covers all remaining expenses

Several charts also visualise how your wealth develops before and after retirement.

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What is bridge capital?

Traditional FIRE calculators often assume your investment portfolio must finance every year after retirement.

In reality, many people later receive pension income, rental income or other recurring cash flows.

This calculator therefore calculates bridge capital.

Bridge capital represents the amount of wealth needed only for the years in which your expenses exceed your other income.

Once future income permanently covers all remaining expenses, your investment portfolio no longer needs to finance your lifestyle.

This creates a more realistic and flexible FIRE calculation.

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Monte Carlo simulation

Financial markets rarely produce average returns every single year.

The Monte Carlo simulation generates hundreds or thousands of possible market outcomes by varying annual investment returns.

Instead of asking "What happens if everything goes according to plan?", it answers:

"How often is this financial plan likely to succeed under many different market conditions?"

A higher success rate indicates a more resilient financial plan, although no future outcome can ever be guaranteed.

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Disclaimer

This calculator is intended for educational purposes only.

All results depend entirely on the assumptions entered by the user.

Actual investment returns, inflation, taxes, costs and future legislation may differ significantly from these assumptions.

The calculator should therefore be used as a planning tool and not as personal financial or investment advice.

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