FinancialFreedom

FIRE Method & Methodology

Understanding the FIRE method and how we calculate your financial independence number

Last updated: September 24, 2025 • Scope: United States • Amounts shown are USD per year
What is the FIRE Method?

FIRE stands for Financial Independence, Retire Early. It's a movement and methodology focused on saving and investing aggressively to achieve financial independence much earlier than traditional retirement age.

Core Principles

  • High Savings Rate: Save 25-70% of income vs. traditional 10-15%
  • Frugal Living: Optimize expenses without sacrificing quality of life
  • Index Fund Investing: Low-cost, diversified investment approach
  • Geographic Arbitrage: Live in lower-cost areas when possible

The 25x Rule

The foundation of FIRE is the 25x rule: you need 25 times your annual expenses saved to retire safely.

FIRE Number = Annual Expenses × 25

Based on the 4% safe withdrawal rate from the Trinity Study

Types of FIRE

Lean FIRE

Minimal expenses, typically $40,000-60,000/year. Requires significant lifestyle optimization.

Regular FIRE

Comfortable middle-class lifestyle, typically $60,000-100,000/year. Most common approach.

Fat FIRE

Luxury lifestyle maintained, typically $100,000+/year. Requires higher income or longer timeline.

Why FIRE Works

Mathematical Foundation

The 4% withdrawal rate is based on historical market data showing that a diversified portfolio can safely support 4% annual withdrawals for 30+ years, even through market downturns.

Compound Interest Power

Starting early and investing consistently allows compound interest to work its magic. A 7% average return doubles your money every 10 years.

How We Calculate Your FIRE Number
1

Tier Selection

You choose one option in each category (housing, transportation, food, travel, healthcare, entertainment, shopping).

2

National Anchors

We start from reputable, national datasets (detailed below).

3

Location Scaling

We apply a location multiplier keyed to local rent levels vs. the U.S. typical (Zillow, ZORI).

4

Household Sizing

Housing and transportation are generally household-level; food is per-person and scaled using USDA household adjustments.

Category Anchors & Notes

Housing

Anchor: Typical asking rent and regional differentials (Zillow Research, ZORI).

Method: "Modest" ≈ below-median stock; "Comfortable" ≈ near national typical; "Premium urban condo" reflects prime-metro amenity stock.

Transportation

Anchor: All-in annual ownership cost (AAA, Your Driving Costs).

Transit-heavy tiers: Benchmarked with common big-city monthly passes plus modest rideshare.

Food

Anchor: At-home food costs (USDA Food Plans).

Organic / high-quality: Adds a moderate premium informed by USDA Economic Research Service analyses of organic price differentials.

Travel (per person)

Anchors: Average domestic airfare (Bureau of Transportation Statistics) and typical hotel average daily rates (STR).

Method: Airfare + 3–7 hotel nights + meals; tiers reflect trip frequency and distance (domestic vs. international).

Healthcare

Employer reference: Average single-coverage premium (KFF Employer Health Benefits Survey).

Individual/ACA reference: Marketplace benchmark trends (HealthCare.gov / CMS) plus typical out-of-pocket assumptions for bronze/silver vs. gold.

Entertainment & Shopping

Benchmarks: National spending shares and levels (BLS Consumer Expenditure Survey).

Method: Tier "ladder" brackets the national average up/down for lifestyle differences (from low/free hobbies to premium clubs; from necessities to luxury).

Interpretation & Caveats

• These are national anchors adjusted by simple location multipliers; actual costs vary by city, household makeup, and choices (e.g., car type, miles driven, dining frequency).

• Amounts reflect spending, not tax liabilities.

Organic premiums vary widely by item and market; our organic tier uses a conservative uplift over the USDA "moderate" basket.

Travel tiers assume economy airfare and midscale lodging; peak-season or luxury choices will be higher.

Primary Data Sources
• Zillow Research (ZORI)
• AAA — Your Driving Costs
• USDA Food Plans; USDA Economic Research Service
• Bureau of Transportation Statistics (BTS)
• STR (hotel performance / ADR)
• KFF — Employer Health Benefits Survey
• HealthCare.gov / Centers for Medicare & Medicaid Services (CMS)
• Bureau of Labor Statistics — Consumer Expenditure Survey (CE)

Ready to Calculate Your FIRE Number?

Now that you understand our methodology, take the assessment to get your personalized financial independence calculation.