FIRE Calculator: When Can You Actually Retire?

Published August 2026 | 8 min read

Financial Independence, Retire Early (FIRE) isn't about extreme frugality. It's about math. Specifically: how much do you need to never work again? Use our retirement calculator to find your number.

The 4% Rule (The Foundation)

You can safely withdraw 4% of your investment portfolio each year without running out of money. This means:

Your FIRE Number = Annual Expenses × 25

If you spend $40,000/year, you need $1,000,000 invested.

Calculate Your Savings Rate

Your savings rate determines how fast you reach FIRE:

Assumes 5% real returns after inflation.

Types of FIRE

• Lean FIRE: $25k-40k/year spending, aggressive saving
• Coast FIRE: Save enough early, then let compound growth do the work
• Barista FIRE: Part-time work covers expenses, investments keep growing
• Fat FIRE: $100k+/year spending, requires $2.5M+

The Hidden Cost: Healthcare

Before Medicare at 65, you're on your own:

• ACA marketplace: $400-800/month
• HDHP + HSA: $300-500/month
• Factor this into your annual expenses

Shortcut: Coast FIRE

Instead of saving your full FIRE number, save enough that compound growth gets you there by traditional retirement age:

• Age 30: $250k invested → grows to $1.5M by age 65 at 5%
• Then you only need to cover living expenses, not save more
• Much less stressful than full early retirement

The Bottom Line

FIRE is possible at almost any income — but it requires saving aggressively and investing consistently. Calculate your number. Pick a strategy. Start today. Even if you don't retire at 40, having the option at 55 is life-changing.

Related: Retirement Calculator | 401k vs IRA Guide | Compound Interest Explained