FIRE Glossary

Your complete guide to Financial Independence and Retirement terminology. Learn the key terms you need to understand on your journey to early retirement.

A B C D E F H I L M P R S T W

A

Asset Allocation

The strategy of dividing your investment portfolio among different asset categories such as stocks, bonds, and cash. Your asset allocation should match your risk tolerance, time horizon, and financial goals.

Example: A common asset allocation rule is "110 minus your age = percentage in stocks." At age 30, you'd have 80% stocks and 20% bonds.

B

Barista FIRE

A variation of FIRE where you achieve partial financial independence and work part-time (often for benefits like health insurance) while your investments continue growing. The term comes from working as a "barista" for benefits while living off investment income.

Example: Saving $500,000 by age 40, then working 20 hours/week while investments cover most living expenses.

C

Coast FIRE

Reaching a point where you've saved enough that you no longer need to contribute to retirement accounts. Your existing investments will grow to support retirement at traditional retirement age. You can "coast" in a lower-stress job or work part-time.

Example: Saving $200,000 by age 30 means you can coast until 65 as it grows to $1.6 million at 7% returns.

Compound Interest

Interest calculated on the initial principal and accumulated interest from previous periods. Often called "interest on interest," it causes wealth to grow exponentially over time.

Example: $10,000 at 7% annual return becomes $76,123 in 30 years due to compounding.
Try our Compound Interest Calculator →

D

Debt Avalanche

A debt repayment strategy where you pay off debts in order of highest to lowest interest rate, regardless of balance. This method saves the most money in interest over time.

Example: Paying off a 22% credit card before a 4% car loan, even if the car loan balance is higher.
Compare strategies with our Debt Calculator →

Debt Snowball

A debt repayment strategy where you pay off debts from smallest to largest balance, regardless of interest rate. Quick wins provide psychological motivation to continue.

Example: Paying off a $500 medical bill before a $10,000 student loan, even if the student loan has higher interest.

E

Employer Match

Free money your employer contributes to your 401k based on your contributions. Common formulas include dollar-for-dollar match up to 3% or 50 cents per dollar up to 6% of salary.

Example: You earn $75,000 and contribute 6% ($4,500). Your employer matches 50% up to 6%, adding $2,250 free money.
Calculate your match with our 401k Calculator →

Expense Ratio

The annual fee charged by mutual funds or ETFs, expressed as a percentage of your investment. Lower expense ratios mean more of your money stays invested and compounds.

Example: A 1% expense ratio on $100,000 costs you $1,000 per year. Over 30 years, high fees can cost hundreds of thousands in lost returns.
See the impact with our Fee Calculator →

F

Fat FIRE

Financial Independence Retire Early with a high standard of living. Typically requires $100,000+ in annual spending and a retirement nest egg of $2.5 million or more.

Example: Saving $3 million to support $120,000/year in retirement expenses.

Financial Independence (FI)

Having enough passive income or invested assets to cover your living expenses without needing to work. You have the freedom to work because you want to, not because you have to.

Example: If your annual expenses are $40,000 and your investments generate $40,000/year, you've achieved FI.

FIRE

Financial Independence, Retire Early. A movement focused on extreme saving and investing to achieve financial freedom decades before traditional retirement age.

Example: Saving 50-75% of income to retire at 40 instead of 65.
Calculate your FIRE number →

FIRE Number

The total amount of money you need to achieve Financial Independence. Calculated using the 4% rule: Annual Expenses × 25 = FIRE Number.

Example: If you spend $50,000/year, your FIRE number is $1,250,000 ($50,000 × 25).

4% Rule

A retirement withdrawal strategy suggesting you can safely withdraw 4% of your portfolio in the first year of retirement, then adjust for inflation each year, with high probability your money will last 30+ years.

Example: With $1,000,000 saved, you can withdraw $40,000 in year one. If inflation is 3%, withdraw $41,200 in year two.

401(k)

A tax-advantaged retirement account offered by employers. Contributions are made pre-tax (reducing current taxable income), and investments grow tax-deferred until withdrawal in retirement. 2025 contribution limit is $23,500 ($31,000 if age 50+).

Example: Contributing $10,000 to 401k reduces your taxable income by $10,000, potentially saving $2,200 in taxes at 22% tax bracket.

H

HSA (Health Savings Account)

A triple tax-advantaged account for healthcare expenses. Contributions are tax-deductible, growth is tax-free, and withdrawals for qualified medical expenses are tax-free. Can be used as retirement account after age 65.

Example: Contributing $4,150/year (2025 individual limit) and investing it long-term for healthcare costs in retirement.

I

Index Fund

A mutual fund or ETF designed to track a market index like the S&P 500. Offers broad diversification, low fees, and historically strong returns. Passive investing strategy favored by FIRE community.

Example: VTSAX (Vanguard Total Stock Market Index) holds over 4,000 US stocks with 0.04% expense ratio.

L

Lean FIRE

Achieving Financial Independence with a minimalist lifestyle, typically spending $25,000-40,000 per year. Requires smaller nest egg but more frugal living.

Example: Living on $30,000/year requires a FIRE number of $750,000 ($30,000 × 25).

Lifestyle Inflation

The tendency to increase spending as income rises. Also called "lifestyle creep." The enemy of FIRE, as it prevents savings rate from increasing with income.

Example: Getting a $20,000 raise but upgrading car and apartment, leaving no extra money to save.

M

Mega Backdoor Roth

An advanced strategy to contribute up to $46,000 additional after-tax dollars to a 401k, then convert to Roth. Requires employer plan that allows after-tax contributions and in-service conversions.

Example: After maxing regular 401k at $23,500 and getting $5,000 employer match, contributing $46,000 after-tax and converting to Roth.

P

Passive Income

Money earned with minimal ongoing effort. Sources include investment dividends, rental property income, royalties, or business income from automated systems.

Example: $1,000,000 in dividend stocks yielding 3% provides $30,000/year passive income.

R

Roth IRA

A retirement account where contributions are made with after-tax dollars, but withdrawals in retirement are completely tax-free. 2025 contribution limit is $7,000 ($8,000 if age 50+). Income limits apply.

Example: Contributing $7,000/year for 30 years at 7% returns grows to $708,000, all withdrawable tax-free in retirement.
Compare Roth vs Traditional IRA →

S

Safe Withdrawal Rate (SWR)

The percentage of your portfolio you can withdraw annually with low risk of running out of money. The 4% rule is the most famous SWR, based on historical data and the Trinity Study.

Example: With $1 million saved and 4% SWR, you can withdraw $40,000/year with 95% confidence your money lasts 30+ years.

Savings Rate

The percentage of your after-tax income that you save and invest. The most important factor determining how quickly you reach FIRE. Higher savings rate = faster path to financial independence.

Example: Earning $75,000 after taxes and saving $37,500 = 50% savings rate = financial independence in ~17 years.

Sequence of Returns Risk

The risk that poor investment returns early in retirement can significantly reduce portfolio longevity, even if average returns are good over time. A major concern for early retirees.

Example: Retiring in 2008 during market crash vs. 2013 during bull market creates vastly different outcomes, even with same average 30-year returns.

T

Traditional IRA

A retirement account where contributions may be tax-deductible (reducing current taxable income), investments grow tax-deferred, but withdrawals in retirement are taxed as ordinary income. 2025 contribution limit is $7,000 ($8,000 if age 50+).

Example: Contributing $7,000 to Traditional IRA may reduce taxable income by $7,000, saving $1,540 in taxes at 22% bracket.

Trinity Study

A landmark 1998 study that analyzed historical portfolio success rates for various withdrawal rates and asset allocations. The foundation for the 4% rule.

Example: Study found 4% withdrawal rate with 50% stocks/50% bonds had 95% success rate over 30-year retirement.

W

Withdrawal Rate

The percentage of your investment portfolio you withdraw each year to fund living expenses in retirement. The 4% withdrawal rate is most commonly used in FIRE planning.

Example: $1,200,000 portfolio with 4% withdrawal rate provides $48,000/year income.