What is a good FI number?

A good FI number is 25 times your annual expenses. For someone spending $40,000 per year, that is $1,000,000. For $60,000 per year, it is $1,500,000. Your FI number is personal and depends entirely on the lifestyle you want to maintain.

How do I calculate my FI number?

Multiply your annual expenses by 25. This is based on the 4% safe withdrawal rate from the Trinity Study, which showed that withdrawing 4% of your portfolio annually has historically sustained a 30+ year retirement.

Is the 4% rule still valid?

The 4% rule remains a widely accepted starting point backed by decades of historical data. Some financial planners suggest using 3.5% for added safety, while others argue that flexible spending strategies allow for higher withdrawal rates. The key is having a plan and adjusting as needed.

Should I include Social Security in my FI number?

Social Security can reduce the amount you need to save. If you expect $20,000 per year from Social Security, your portfolio only needs to cover the gap. However, many in the FI community prefer to plan without it as a conservative approach and treat it as a bonus.

What is the difference between Lean FIRE, Regular FIRE, and Fat FIRE?

Lean FIRE targets $25,000 to $40,000 per year in spending ($625K to $1M portfolio). Regular FIRE targets $40,000 to $70,000 ($1M to $1.75M). Fat FIRE targets $100,000+ ($2.5M+). The right choice depends on your desired lifestyle and cost of living.

Resources

FI Number Calculator

One number changes everything. Your FI number is the portfolio size where work becomes optional. Find yours in seconds.

What Is a FI Number?

Your FI number is Annual Expenses × 25. Once your investments reach this amount, the 4% withdrawal rate covers your lifestyle — forever.

Slide to explore — how much do you spend monthly?

$1,500/mo $15,000/mo

Annual Expenses

FI Number (25×)

Annual Withdrawal

Every $100/month you cut permanently reduces your FI number by $30,000

Full FI Calculator

Model your complete path — current investments, contributions, returns, and projected timeline.

Your Scenario

Current Age 35

Monthly Expenses $4,000

Current Investments $50,000

Monthly Contribution $1,500

Annual Return 7%

FI Target Date October 2048 Age 57

FI Number $1,200,000 25x annual expenses

Annual Withdrawal $48,000 $1,200,000 × 4%

Every dollar counts. Focus on increasing the gap between income and expenses. Use the sliders to explore scenarios.

How Do I Factor Pensions & Social Security Into My FI Number?

Want to factor in Social Security, pensions, debt payoff, and more? Our FI Planning Tool builds a complete, personalized roadmap — free.

Basic Calculator

FI Number (25x rule)
Timeline projection
Growth chart

FI Planning Tool

Everything in Basic, plus:
Social Security & pensions
Debt payoff modeling
Multiple scenarios
Progress tracking
Personalized milestones

Free forever — no credit card required

Which FIRE Is Right for You?

There is no one-size-fits-all. Choose the level that matches your values and lifestyle.

Lean FIRE

$25K-$40K/yr

$625K-$1M

Minimal spending, maximum freedom. You have optimized expenses aggressively and are comfortable living simply. Geographic arbitrage — low cost-of-living areas or countries — makes this very achievable.

Best for: Minimalists, frugality enthusiasts, international expats

Regular FIRE

$40K-$70K/yr

$1M-$1.75M

A comfortable middle-class lifestyle without the paycheck. Occasional travel, dining out, hobbies, and a modest home. This is where most ChooseFI community members aim.

Best for: Most FI seekers, families, suburban homeowners

Fat FIRE

$100K+/yr

$2.5M+

All the freedom with zero lifestyle compromises. Premium healthcare, frequent travel, higher-cost-of-living areas. Requires either very high income, long timeline, or entrepreneurial success.

Best for: High earners, entrepreneurs, those in expensive metros

Coast FI

Varies

Already invested enough

You have invested enough that compound growth will carry you to traditional retirement age without another dollar added. You only need to cover current expenses — no more saving required.

Best for: Early starters, those wanting less pressure, career changers

Barista FIRE

Partial coverage

50-80% of full FI

Your investments cover most expenses and a low-stress part-time job fills the gap. Named after the strategy of working at places like Starbucks for health benefits.

Best for: Those who want a safety net, healthcare coverage seekers