FIRE Calculation Guide

How much do you need for an early retirement?

Knowing how much money you need to retire early is the key question of the FIRE journey. This guide explains how to estimate your 'FIRE Number', the 4% rule, and how FireNation helps you plan.

Your FIRE Number – The Simple Formula

A common way to estimate the required amount is the FIRE Number formula:

FIRE Number ≈ Annual Expenses × 25

This rule comes from the historical idea that withdrawing 4% of your portfolio per year allows it to last 30 years. If you spend 40,000 a year, you need about 1,000,000 (40,000 × 25).

This is just a starting point. Your number depends on taxes, country, and lifestyle. FireNation helps you refine this.

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Step 1 – Define your lifestyle

Some want total retirement, others part-time work (Barista FIRE).

  • At what age do you want work to become optional?
  • How much do you want to spend per year?
  • Will you have a pension later?

In FireNation, define different life phases to see the required capital.

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Step 2 – Estimate your annual expenses

Portfolio size depends more on expenses than income. The less you spend, the faster you are free.

  • Start from your current budget, remove work-related expenses.
  • Add future expenses (travel, health).

FireNation tracks your real expenses to create a realistic FIRE scenario.

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Step 3 – Choose a Withdrawal Rate

The 4% rule is a baseline. For more safety, many target 3% or 3.5%.

  • At 4%: Expenses × 25
  • At 3.5%: Expenses × ~29
  • At 3%: Expenses × ~33

Test different rates in FireNation to see the impact on required capital.

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Step 4 – Calculate your Target

Once expenses and rates are defined, calculate your precise target.

Example: 50,000 expenses ÷ 0.035 rate ≈ 1,428,571 required portfolio.

FireNation calculates this for you and displays your progress as a percentage.

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Step 5 – Estimate Time Required

Time depends on your savings rate. Going from 10% to 50% savings reduces working years by several decades.

FireNation combines savings rate and return to estimate your remaining years.

Risks and Reality

Early retirement carries risks (markets, inflation).

  • Stress-test your plan with lower returns.
  • Be flexible with withdrawals.
  • Plan safety margins.

Use FireNation's optimistic and conservative scenarios.

How FireNation helps you

FireNation connects budget, savings, and investing into one model.

  • ✓Track real expenses.
  • ✓Calculate your FIRE number automatically.
  • ✓See your progress.
  • ✓Simulate different savings rates.

Find your FIRE Number

Stop guessing. Use your real numbers to explore your future.

Create your free account to calculate your number and build your plan.

Calculate my FIRE Number