Financial Terms Glossary

Financial jargon explained in plain English. Each term links to a PennyCalc tool where you can see the math for yourself.

A

Adjusted Gross Income (AGI): Your total income from all sources (wages, interest, capital gains, business profit) minus specific deductions like student loan interest, IRA contributions, and self-employment taxes. AGI is the number the IRS uses to determine your tax bracket and eligibility for various tax credits. It's lower than gross income but higher than taxable income because it doesn't account for the standard deduction or itemized deductions.; Calculate yours →
Amortization: The process of paying off a loan through regular payments that include both principal and interest. An amortization schedule shows exactly how much of each payment goes toward principal (building equity) vs. interest (lender's fee). Early in a loan term, most of your payment is interest; by the end, most is principal. Mortgages and auto loans are fully amortized, meaning you own the asset free-and-clear when the loan ends.; See an amortization schedule →
Annual Percentage Rate (APR): The yearly cost of borrowing expressed as a percentage. APR includes the interest rate plus other fees and costs associated with the loan, so it's higher than the base interest rate. A credit card advertised at 5% APR will cost you 5% annually on your outstanding balance. APR makes it easier to compare loans with different fee structures because it's standardized.; Compare APRs →
Asset Allocation: The mix of different types of investments (stocks, bonds, real estate) in your portfolio. A common allocation for a young investor might be 80% stocks and 20% bonds; for a retiree, it might be reversed. Asset allocation is the largest driver of investment returns and risk. Diversifying across different asset classes reduces the risk that any one type of investment tanks when you need the money.

B

Basis (Cost Basis): The original amount you paid for an investment. When you sell, your capital gain is the difference between the sale price and your basis. If you bought 100 shares at $50 and sold at $75, your basis is $5,000 and your capital gain is $2,500. Basis also accounts for dividends reinvested, stock splits, and adjustments for inherited assets. Tracking basis accurately is critical for calculating taxes owed on investment sales.; Calculate capital gains →
Bond: A loan you make to a company or government that pays you interest in return. When you buy a bond, you're lending money; the issuer agrees to pay you interest (called a coupon) annually or semi-annually, then return your principal at maturity. Bonds are generally lower risk than stocks but also offer lower returns. Government bonds are safest; corporate bonds offer higher yields but higher risk of default.

C

Capital Gains: Profit from selling an investment for more than you paid. Long-term capital gains (from assets held over 1 year) are taxed at favorable rates: 0%, 15%, or 20% depending on your income. Short-term gains (from assets held under 1 year) are taxed as ordinary income at rates up to 37%. This tax difference makes holding investments longer valuable—not just for compounding returns, but also for tax savings.; Calculate capital gains tax →
Catch-Up Contribution: Extra contributions you can make to retirement accounts if you're age 50 or older. The IRS allows these to help older workers catch up on retirement savings. For 2026, you can contribute an extra $7,500 to a 401(k) or $1,000 to an IRA beyond the standard limits. This is one of the most valuable tax breaks for older workers trying to accelerate retirement savings.
Compound Interest: Interest earned on interest. When your investment grows, the growth itself generates additional growth. Over decades, compound interest is the most powerful wealth-building tool available. Albert Einstein supposedly called it the eighth wonder of the world. Starting retirement savings early (even with small contributions) beats starting late with large contributions, because compound interest has more time to work.
Contribution Limit: The maximum amount you can contribute to a retirement or education savings account in a calendar year. These limits are set by the IRS and adjust annually for inflation. For 2026, the 401(k) limit is $23,500 and the IRA limit is $7,000 (higher if you're over 50). Once you hit the limit, you can't contribute more that year, even if you want to.
Cost of Living: The amount you need to spend to maintain a certain standard of living in a given location. Includes rent/mortgage, food, utilities, transportation, healthcare, and other essentials. Cost of living varies dramatically by location—San Francisco costs 2-3x more than rural areas. When comparing job offers or planning retirement, cost of living is as important as salary because it determines your actual purchasing power.

D

Debt-to-Income Ratio (DTI): Your monthly debt payments divided by your gross monthly income. If you earn $5,000 monthly and pay $1,000 in debt (mortgage, auto loan, credit card), your DTI is 20%. Most lenders require a DTI below 43% to qualify for a mortgage. DTI shows how much of your income goes to debt service vs. living expenses and savings. The lower your DTI, the easier you can qualify for loans and the more you have for financial goals.; Calculate your DTI →
Depreciation: The decline in an asset's value over time. Cars depreciate fastest (losing 20% of value in the first year). Real estate typically appreciates (gains value), but depreciation is a technical concept used for tax purposes where real estate owners deduct a portion of the building's cost annually. For personal finance, depreciation means the car you buy loses significant value immediately, making vehicles a wealth-draining expense compared to investments.
Diversification: Spreading investments across different asset classes, sectors, and geographies to reduce risk. Instead of putting all money in one stock, you hold multiple stocks, bonds, and real estate. If one investment tanks, others hold up. Diversification doesn't guarantee profits, but it significantly reduces the chance of catastrophic losses. Low-cost index funds provide automatic diversification across hundreds of companies.
Dollar-Cost Averaging (DCA): Investing a fixed amount at regular intervals (like $500 monthly) regardless of market conditions. This strategy removes the stress of trying to time the market because you invest consistently. When prices are high, your fixed investment buys fewer shares; when prices are low, it buys more shares. Over time, DCA smooths out market volatility and historically produces good results, especially for retirement accounts.
Down Payment: The amount of money you pay upfront when buying something (usually a home or car), with the rest financed through a loan. A larger down payment means a smaller loan, lower monthly payments, and often a better interest rate. It also determines whether you pay PMI (on mortgages under 20% down). Down payments are critical for reducing total interest paid and building immediate equity in the asset.

E

Effective Tax Rate: Your total tax bill divided by your total income. If you earn $100,000 and pay $15,000 in federal tax, your effective tax rate is 15%. This is different from your marginal tax rate (the tax rate on your next dollar of income). The U.S. uses progressive tax brackets, so your effective rate is always lower than your highest marginal rate. Understanding effective tax rate helps you compare tax burdens across different income levels.; Calculate your effective tax rate →
Employer Match: Employer contributions to your 401(k) or retirement account, typically as a percentage of your contribution. Common structures: "100% of the first 3%" (if you contribute 3% of salary, employer adds 3% too) or "50% of the first 6%". Employer match is essentially free money and is the best return on investment available in most 401(k)s. Not capturing full employer match is like leaving a raise on the table. Always contribute enough to get the full match.
Equity: Your ownership stake in an asset after accounting for debt. If your house is worth $400,000 and you owe $300,000 on the mortgage, you have $100,000 in equity. For investments, equity refers to stocks—literally owning a piece of a company. Building equity over time is how wealth is created: by paying down debt or watching investments appreciate.
Escrow: Money held by a neutral third party during a transaction until conditions are met. In real estate, escrow protects both buyer and seller: the buyer deposits funds, and they're released only after inspection and title verification. In mortgages, escrow refers to your monthly payment includes property taxes and insurance held in an account and paid on your behalf. This ensures taxes and insurance don't lapse.
Expense Ratio: The annual cost of owning a mutual fund or ETF, expressed as a percentage of assets. A fund with a 0.05% expense ratio costs $5 per year for every $10,000 invested. Low-cost index funds charge 0.03-0.10%; actively-managed funds often charge 1%+ annually. Over decades, even tiny differences in expense ratios compound dramatically because you're paying fees on fees' returns. Index funds with expense ratios under 0.10% are best for most investors.

F

FICA (Federal Insurance Contributions Act): The payroll tax that funds Social Security and Medicare. Employees pay 6.2% for Social Security (on income up to $168,600 in 2026) and 1.45% for Medicare (no limit), totaling 7.65%. Your employer pays the same amount. Self-employed people pay both sides: 15.3%. FICA taxes are withheld from your paycheck automatically and don't show up as federal income tax—they're separate and mandatory for all workers.; See FICA on your paycheck →
Fixed-Rate Mortgage: A mortgage where the interest rate stays the same for the entire loan term (typically 15 or 30 years). Your monthly payment never changes, making budgeting predictable. If interest rates rise, you're protected because your rate is locked. Fixed-rate mortgages are the safest option for most homebuyers because they eliminate interest rate risk. The tradeoff: fixed rates are slightly higher than the starting rate on adjustable-rate mortgages (ARMs).; Calculate mortgage payments →
Front-End Ratio: Your housing costs (mortgage, property tax, insurance, HOA) divided by gross monthly income. Lenders typically require this to be below 28%. If you earn $5,000 monthly, your housing costs shouldn't exceed $1,400. This is stricter than the debt-to-income ratio because it focuses only on housing, not total debt. The front-end ratio ensures you have income left for other expenses and savings.

G

Gross Income: Total income from all sources before any deductions or taxes. For an employee, gross income is your salary before taxes, FICA, or retirement contributions are withheld. For a freelancer, it's all revenue before business expenses. Lenders use gross income to determine loan amounts because it represents your full earning power, even though your take-home (net) income is lower after taxes and deductions.

I

Index Fund: A fund that tracks a market index, like the S&P 500. Instead of trying to beat the market (which most active managers fail to do), an index fund simply owns all 500 companies in the S&P 500 in the same proportions. Index funds have minimal fees (often under 0.05%), automatic diversification, and historically outperform 80%+ of actively-managed funds. For most investors, low-cost index funds are the best choice for building long-term wealth.; Model index fund growth →
Interest Rate: The cost of borrowing, expressed as a percentage of the borrowed amount per year. A 6% mortgage on a $300,000 loan costs roughly $18,000 in interest the first year. Interest rates vary based on credit risk (higher for worse credit), loan type, and economic conditions. Even a 1% difference in interest rate costs tens of thousands of dollars over the life of a loan, making rate shopping critical before borrowing.; See impact of interest rates →
IRA (Individual Retirement Account): A personal retirement savings account with tax advantages. Traditional IRAs offer upfront tax deductions (lower your taxes this year), while Roth IRAs offer tax-free withdrawals in retirement. Anyone with earned income can open an IRA; contribution limits for 2026 are $7,000 ($8,000 if over 50). IRAs are essential for self-employed people and anyone with investment savings outside of a 401(k).; Model Roth IRA growth →

L

Loan-to-Value Ratio (LTV): Your loan amount divided by the property's value. If you borrow $300,000 for a $400,000 home, your LTV is 75%. Lower LTV is better—it means more equity and lower lender risk. Mortgages with LTV above 80% require PMI. FHA loans allow LTV up to 96.5%, making them appealing to first-time homebuyers, but they also require mortgage insurance for the life of the loan. LTV directly affects your borrowing costs and terms.; Calculate your LTV →

M

MAGI (Modified Adjusted Gross Income): Your AGI with certain deductions added back in for eligibility purposes. The IRS uses MAGI to determine eligibility for tax credits, deductions, and retirement accounts. For example, you can't contribute to a Roth IRA if your MAGI exceeds $150,000 (single, 2026). MAGI is typically higher than AGI because it includes items like foreign earned income and certain deductions. Understanding your MAGI is critical for tax planning.; Calculate your MAGI →
Marginal Tax Rate: The tax rate on your next dollar of income. If you're in the 22% tax bracket, that's your marginal rate—your next dollar of income is taxed at 22%. This is different from your effective tax rate (average rate on all income). Your marginal rate is what matters for decisions: earning an extra $1,000 costs you roughly $220 in federal tax (22% marginal rate) plus state taxes. Marginal rate is critical for understanding whether to take raises, bonuses, or pursue side income.; Find your marginal tax rate →
Mortgage Insurance (PMI): Insurance required when you put down less than 20% on a home. PMI protects the lender if you default; it doesn't protect you. It costs 0.3%-1.5% annually of your loan amount, added to your monthly payment. For a $300,000 loan with 0.5% PMI, that's $1,500 yearly ($125/month). You can stop paying PMI once you reach 20% equity, either through principal payments or home appreciation. PMI makes smaller down payments more expensive, which is why 20% down is considered ideal.; Calculate with and without PMI →

N

Net Income: Income after all deductions, taxes, and expenses. For employees, it's your take-home pay (gross salary minus taxes, FICA, and benefits). For business owners, it's revenue minus business expenses and taxes. Net income is what actually hits your bank account and is what matters for budgeting and financial planning. Your net income determines your ability to save and invest.
Net Investment Income Tax (NIIT): A 3.8% additional tax on investment income for high earners. If your modified AGI exceeds $200,000 (single) or $250,000 (married), the excess investment income (interest, capital gains, dividends) is taxed an additional 3.8%. This effectively raises capital gains rates from 15% to 18.8% for high earners. NIIT is the reason some wealthy investors pay attention to tax-loss harvesting and timing of asset sales.

P

Principal: The original amount borrowed in a loan or the original amount invested. For a $300,000 mortgage, the principal is $300,000. Interest is what you pay on top of principal. Early in a loan, most payments go toward interest; later, more goes toward principal. Building principal in savings and investments is how wealth accumulates, whereas paying principal on debt is how you eliminate it.
Property Tax: Annual tax assessed by local government based on property value. Rates vary dramatically by location: from under 0.5% in Louisiana to over 2% in New Jersey. On a $400,000 home at 1% tax rate, you pay $4,000 annually. Property taxes fund schools, roads, and local services. Unlike mortgage interest, property taxes aren't deductible beyond $10,000 for most people, making them a pure housing cost that factors heavily into total homeownership expenses.; Compare property taxes by state →

Q

QBI Deduction (Qualified Business Income): A deduction allowing self-employed people and small business owners to deduct up to 20% of qualified business income from taxable income. If you earn $100,000 in self-employment income, you might deduct $20,000, reducing taxable income to $80,000. QBI deduction effectively reduces tax rates for business owners, though it phases out for high earners and has complex rules. Strategically timing income and expenses can maximize QBI deductions.; Calculate QBI impact →
Qualified Dividend: Dividend income taxed at favorable long-term capital gains rates (0%, 15%, or 20%) instead of ordinary income rates. To be "qualified," dividends must come from U.S. corporations or certain foreign companies, and you must hold the stock for specific periods. Unqualified dividends are taxed as ordinary income at rates up to 37%. The tax difference is huge: a $1,000 qualified dividend might cost $150 in tax (15%) vs. $370 (37%) for unqualified dividends.

R

Required Minimum Distribution (RMD): The minimum amount you must withdraw from traditional retirement accounts starting at age 73 (as of 2023; age increases gradually). The IRS requires RMDs to ensure they collect taxes on money in retirement accounts eventually. RMD amounts are based on your age and account balance. Failure to take RMDs results in a 25% penalty on the shortfall (reduced to 10% if corrected quickly). Roth IRAs have no RMDs during the owner's lifetime.
Roth Conversion: Converting money from a traditional (pre-tax) IRA to a Roth (post-tax) IRA. You pay taxes on the conversion amount but then all future growth is tax-free. Roth conversions are strategic for high earners wanting to shift income into Roth accounts, or for people who expect higher tax rates in retirement. Conversions must be done carefully to avoid pushing you into a higher tax bracket in the conversion year.; Model Roth strategy →
Roth IRA: A retirement account where contributions are after-tax (not deductible) but all growth is tax-free and withdrawals in retirement are tax-free. Roth IRAs have no RMDs, making them ideal for leaving wealth to heirs. Contribution limits for 2026 are $7,000 ($8,000 if over 50). Income limits apply: you can't contribute if your MAGI exceeds $150,000 (single). Roth accounts are perfect for young people in low tax brackets and high earners using backdoor Roth conversions.; Calculate Roth growth →

S

S&P 500: An index of 500 large U.S. companies representing roughly 80% of total U.S. stock market value. The S&P 500 is the benchmark for stock market performance: if the S&P 500 is up 10% this year, that's a good year for stocks. Most investment professionals recommend index funds tracking the S&P 500 rather than trying to pick individual stocks. Historically, S&P 500 returns average about 10% annually over decades.
Self-Employment Tax: Social Security and Medicare taxes paid by self-employed people. Because self-employed workers don't have employers withholding these taxes, they pay both the employee and employer portions: 15.3% of net self-employment income (12.4% for Social Security on the first $168,600 in 2026, plus 2.9% for Medicare). Self-employed people can deduct half of self-employment tax as a business expense. This is why self-employed income faces higher overall tax rates than W-2 wages.; Calculate self-employment tax →
Standard Deduction: A fixed deduction available to all taxpayers, used instead of itemizing individual deductions. For 2026, the standard deduction is roughly $14,600 (single) and $29,200 (married filing jointly), adjusting annually for inflation. You can either take the standard deduction or itemize specific deductions (mortgage interest, property taxes, charitable gifts) and claim the larger amount. Most Americans use the standard deduction because it's higher than their itemized deductions.; See impact of standard deduction →
Student Loan Interest Deduction: A deduction allowing you to reduce taxable income by up to $2,500 of student loan interest paid in the year, if you meet income requirements. This deduction is "above the line," meaning you get it even if you take the standard deduction (unlike itemized deductions). If you pay $3,000 in student loan interest and are in the 22% tax bracket, this deduction saves you about $550 in taxes. Income limits apply: the deduction phases out at $75,000 (single) and $155,000 (married).; Model student loan payoff →

T

Tax Bracket: A range of income taxed at a specific rate. For 2026 (single filers), income from $0-$11,600 is taxed at 10%, $11,601-$47,150 is taxed at 12%, etc. These brackets adjust annually for inflation. The U.S. uses marginal tax brackets, meaning only income within each bracket is taxed at that rate—you don't pay 12% on your entire income if you cross into the 12% bracket. Understanding your bracket helps you plan charitable giving, investment timing, and retirement account contributions.; Find your tax bracket →
Tax-Deferred: Investments or accounts where you don't pay tax on growth until you withdraw money. Traditional 401(k)s and traditional IRAs are tax-deferred: investments grow without annual taxes, but you pay tax on withdrawals. Tax-deferred accounts are powerful because they let compounding work without annual tax drains. The tradeoff: you must pay taxes eventually, and you can't access money before age 59½ without penalties.
Tax-Loss Harvesting: Selling investments at a loss to offset capital gains and reduce taxes. If you sold stock for a $5,000 gain and have another investment down $3,000, you sell the losing investment, reducing net capital gains to $2,000. You can also use losses to offset ordinary income (up to $3,000 per year; excess carries forward). Tax-loss harvesting is a powerful strategy for taxable accounts because it costs nothing and can save thousands in taxes over time.
Traditional IRA: A retirement account where contributions may be tax-deductible, reducing your current taxable income, but you pay tax on withdrawals in retirement. Traditional IRAs are ideal if you want to lower your current tax bill and expect to be in a lower tax bracket in retirement. Contribution limits for 2026 are $7,000 ($8,000 if over 50). You must start taking required minimum distributions at age 73, and withdrawals before age 59½ face a 10% penalty.; Compare Traditional vs. Roth →

V

Variable-Rate Mortgage (ARM): A mortgage where the interest rate changes periodically (usually after an initial fixed period). An ARM might be 5% fixed for 7 years, then adjustable annually after. ARMs start with lower rates, making them attractive, but your rate and payment can spike dramatically when the fixed period ends. ARMs are risky unless you plan to sell or refinance before rates adjust. Fixed-rate mortgages are safer for most homebuyers.
Vesting: The schedule determining when employer contributions to your retirement account become yours permanently. Some employers allow immediate vesting (your employer match is yours right away), while others use a vesting schedule (you get 20% per year over 5 years). Until fully vested, if you leave the company, you forfeit unvested employer contributions. Always check vesting schedules before leaving an employer—sometimes waiting a few months means thousands of dollars in additional vesting.

W

W-2: The tax form your employer sends showing your annual wages and taxes withheld. You receive a W-2 if you're an employee earning more than $600. It shows gross wages, federal and state tax withholding, FICA taxes, and other deductions. You use information from your W-2 to file your tax return. If too much tax was withheld, you get a refund; if too little, you owe money. Self-employed people receive 1099 forms instead.
W-4: The form you fill out when starting a job that tells your employer how much to withhold from your paycheck for federal income tax. It accounts for your filing status, number of dependents, and additional income. If you expect a refund every year, your W-4 is withholding too much (you're giving the government an interest-free loan). If you owe money each April, your W-4 is withholding too little. You can adjust your W-4 anytime to fine-tune withholding.; Calculate optimal withholding →
Withholding: The amount your employer (or you, if self-employed) withholds from paychecks to send to the IRS and state for taxes. Withholding is advance payment of your tax bill—ideally matching your actual tax liability so you neither owe nor get a refund. Under-withholding means you owe money April 15th; over-withholding means you get a refund. Self-employed people must make quarterly estimated tax payments because no employer withholds for them.; Check your withholding →