FIRE stands for Financial Independence, Retire Early. The goal is to build enough invested savings that work becomes optional; people may retire, work part-time, change careers, or simply gain flexibility.

How do I calculate a FIRE number?

A common starting point is yearly spending multiplied by 25, which corresponds to a 4% starting withdrawal assumption. It is a planning shortcut, not a guarantee.

Should I use a nominal or real return for FIRE planning?

Use a real return when the plan is expressed in today's dollars. A real return is growth after inflation, so inflation should not be subtracted a second time.

FIRE Planning for Beginners: A Simple Way to Find Your Number

Financial independence means having enough invested that work becomes optional. FIRE stands for Financial Independence, Retire Early, but the goal can also support part-time work, a career change, or simply more flexibility.

Your FIRE number and the 4% starting point

Your FIRE number is the portfolio amount you are aiming for. A common starting point is yearly spending × 25, which corresponds to a 4% starting withdrawal assumption. Spending $50,000 a year gives a starting target of $1,250,000. This is a planning shortcut, not a guarantee.

The four numbers that shape a first estimate

Invested today is the money already working toward the goal.
Yearly spending sets the size of the target portfolio.
Yearly income minus spending is the surplus added to the plan, or the shortfall withdrawn from it.
Growth after inflation keeps the projection in today's purchasing power. Do not subtract inflation again from an assumption that is already real.

How to read the result

The calculator gives one primary estimate: the age when the projected portfolio reaches the target, the amount needed, and the current yearly surplus or shortfall. A result of “not reached” is a prompt to review spending, yearly surplus, timing, or assumptions. An “already independent” result still needs a careful review of spending and limitations.

The optional CoastFI view asks whether today's invested amount could grow to the same target by a chosen age with no new contributions. It is a second planning lens, not a replacement for the main result.

Limits and practical next steps

Markets do not grow in a straight line. Return order, taxes, account rules, changing spending, and future inflation can all change the outcome. The standard projection uses one deterministic real-return assumption and applies yearly cash flow at year end. Historical analysis, scenario evidence, annual details, and methodology are available separately for deeper review.

Start with honest spending that includes the costs investments need to cover.
Compare the standard starting point with a more cautious planning approach.
Build the yearly surplus through regular contributions or lower recurring costs.
Revisit the estimate as your life, savings, and evidence change.

Frequently asked questions

What does FIRE mean?: FIRE stands for Financial Independence, Retire Early. The goal is to build enough invested savings that work becomes optional; people may retire, work part-time, change careers, or simply gain flexibility.
How do I calculate a FIRE number?: A common starting point is yearly spending multiplied by 25, which corresponds to a 4% starting withdrawal assumption. It is a planning shortcut, not a guarantee.
Should I use a nominal or real return for FIRE planning?: Use a real return when the plan is expressed in today's dollars. A real return is growth after inflation, so inflation should not be subtracted a second time.

Try the FIRE calculator, then learn more about real returns and setting regular contributions.