Updated 2026-10-22 · Abacvia
Personal-finance words defined the way the rest of this site works: plain English, real numbers, no jargon explaining jargon. Every term links to the calculator or guide where you can actually use it.
The shorthand FIRE target: accumulate 25 times your annual spending, because a portfolio that size historically supported a roughly 4% yearly withdrawal (the safe withdrawal rate). Spend $40,000 a year and the number is $1,000,000. Adjust the withdrawal rate and the multiplier moves with it — about 33× at 3%.
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A budget framework that splits after-tax income into three buckets: 50% needs, 30% wants, 20% savings and extra debt payoff. It is a starting ratio, not a grade — the value is the triage, and the calculator shows where your real spending lands against it.
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The schedule that splits a level loan payment between interest and principal each period. Early payments are mostly interest, because interest is charged on the principal still owed — so the balance falls slowly at first and faster near the end.
The yearly cost of borrowing — interest plus certain fees — expressed as one percentage so different loans can be compared. A credit card at 24% APR charges roughly 2% of the balance per month (24 ÷ 12), which is exactly how the credit card interest calculator compounds it.
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The yearly return on savings with compounding already included, expressed as one percentage. An account paying 4.8% compounded monthly actually yields about 4.9% over a full year; APY is the number that has done that math for you, which is why comparing APY to APR directly is misleading.
A FIRE variant where a part-time or lower-stress job covers essential expenses — in the U.S. frequently just to keep health insurance — while the invested portfolio keeps compounding toward full independence. The portfolio only needs to cover the gap between spending and part-time income, so the target arrives years sooner.
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Getting paid every two weeks — 26 paychecks a year, instead of 24 on a semi-monthly schedule. Two months a year contain three paychecks, which budgeters use as a natural boost to savings or debt; the catch is budgeting against an income that does not arrive in tidy monthly halves.
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A plan for money before it arrives: expected income assigned to expected expenses and savings for a period, usually a month. A budget is working when the planned numbers track the actual ones closely enough to act on — the gap between them is budget variance.
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The difference between what a budget planned and what actually happened, per category. Variance is information, not failure: a repeated negative variance means the plan was wrong for that category and should be re-budgeted, not defended.
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Money in minus money out over a period. Positive cash flow means income exceeded expenses and the difference can be saved or sent to debt; negative means the gap was covered by savings or borrowing. Timing matters as much as direction — rent due on the 1st against a paycheck on the 15th is a cash-flow problem even when the month nets positive.
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A FIRE variant where you save aggressively early, then stop contributing entirely and let compounding carry the portfolio to 25× your spending by conventional retirement age. The later you start, the larger the required early pile — the trade the projection in the FIRE calculator makes concrete.
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Interest that earns interest: each period’s interest is added to the balance, and the next period’s interest is computed on the new total. Over 30 years, $10,000 at 7% grows to about $76,000 with compounding versus $31,000 with simple interest alone. Projections assume constant returns — see the financial disclaimer.
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The share of your revolving credit limits currently in use — balances divided by limits, per card and in total. It is a major input to credit scores, and the practical lever is timing: paying a balance before the statement closes reports a lower utilization than paying after, even if you pay in full either way.
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Paying off debts ordered by interest rate, highest first, while paying minimums on the rest. It is the mathematically cheapest order — total interest is minimized — though progress can feel slow when the highest-rate debt is also a large one.
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Paying off debts ordered by balance size, smallest first, while paying minimums on the rest. It costs slightly more interest than the avalanche but closes accounts sooner, which behavioral research links to better follow-through.
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Monthly debt payments divided by monthly gross income, as a percentage. Lenders use it to judge capacity for new borrowing — above roughly 43%, most U.S. mortgages are out of reach — and yours comes straight from the income and payment numbers an income-vs-expenses view already organizes.
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Spending that can be postponed or skipped without breaking anything — dining out, streaming, hobbies — as opposed to fixed obligations. Not the same as waste: discretionary spending is where the deliberate trade-offs live, and it is the bucket the 50/30/20 rule reserves 30% for.
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Cash set aside strictly for unplanned expenses — job loss, medical bills, urgent repairs — so they do not become debt. Common targets are $500–$1,000 for a starter fund, then 3–6 months of essential expenses; the calculator turns your actual monthly essentials into the number.
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Financial independence, retire early: saving and investing aggressively enough that work becomes optional years or decades ahead of the conventional age. The math is the 25x rule applied to your spending; the honest hard parts — health insurance, sequence risk, four decades of changing plans — are what the beginner guide spends its time on. Projections assume market returns; see the financial disclaimer.
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Costs that stay the same every period regardless of use — rent, insurance premiums, minimum loan payments. They are the floor of a budget and the slowest to change, which is why shrinking the fixed base is treated as a structural win rather than a one-off saving.
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The window between a credit card’s statement closing and its payment due date — at least 21 days in the U.S. — during which new purchases accrue no interest if the previous balance was paid in full. Carry a balance once and the grace period usually disappears until the balance is cleared in full again.
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Everything earned before deductions — wages, bonuses, side income. Budgets are usually built on net income instead, since that is what actually arrives; gross matters for ratios like DTI and for limits keyed to salary.
A savings account paying materially more than the national average, usually at online banks with no branch costs. It is the standard home for an emergency fund: the money stays liquid and FDIC-insured up to the legal limit, and the rate floats, so the yield at opening is not guaranteed to last.
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The general rise in prices over time, meaning a dollar buys less each year — in recent U.S. history by anywhere from about 2% to 9% annually. It is the reason long-range projections use real return — return minus inflation — rather than headline numbers.
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The tendency for spending to expand to match each raise, so the savings rate never moves. It attacks long-range goals from both ends — a bigger denominator of needs and nothing extra flowing to savings — which is why the fix is banking a fixed share of every raise before it becomes the new normal.
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How quickly an asset can become spendable cash at full value. Cash is perfectly liquid; a portfolio takes days; a house takes months and fees. Emergency funds exist because the moments you most need money are exactly the moments illiquid assets are expensive to sell.
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The smallest payment a lender will accept without the account counting as delinquent — for credit cards typically 1–2% of the balance plus interest and fees. It is engineered to keep the debt alive: minimums alone can stretch a manageable balance into two decades or more of payments.
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What actually arrives after taxes, insurance premiums, and other withholdings are subtracted from gross income. It is the only honest basis for a budget — you cannot assign money that never reached you.
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Everything you own minus everything you owe: assets (cash, savings, investments, property) less liabilities (loans, card balances). It is the stock measure of finances where a budget is the flow measure — negative early on is common, and the trend matters more than the level.
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What the next-best use of the same money would have gotten you. Every dollar aimed at one goal is implicitly not aimed at another — extra debt payments versus investing is the classic trade — which is exactly the ordering question the financial order of operations exists to answer.
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A fee charged when a payment pulls a checking balance below zero — in the U.S. often $25–35 per incident. It is the expensive version of running out of buffer, which is why a small cash cushion is cheaper than any fee schedule.
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Routing money to savings or extra debt payoff the moment income arrives, before spending gets a chance — by automatic transfer, not willpower. It inverts the usual save-whatever-is-left approach, whose typical remainder is nothing.
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A fraud that pays earlier “investors” with newer investors’ money while claiming the returns come from a real strategy. The tells are the red flags in the scam guide: returns that are high, steady, and guaranteed all at once, plus pressure and secrecy about the underlying investments.
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The amount borrowed, or remaining on a loan, separate from interest — interest is the price of holding that principal. Extra payments go straight at principal, which is why even small extra amounts shorten a loan by more than intuition suggests.
An investment’s return after inflation: 7% nominal in a 3%-inflation year is about 4% real (1.07 ÷ 1.03 ≈ 1.039). Long projections that skip this step quietly overstate outcomes, which is why serious FIRE planning treats real return as the honest input. See the financial disclaimer.
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A mental-math shortcut for doubling time: 72 divided by the annual return approximates the years for money to double — at 6%, about 12 years; at 9%, about 8. It falls out of the mathematics of compound interest and stays accurate to within a few months across the typical 4–12% range.
The share of a portfolio you can withdraw each year with low historical risk of running out — the source of the 4% guideline drawn from 30-year retirements. Lower rates mean bigger targets: about 33× spending at 3% versus 25× at 4%. Early or long retirements face sequence risk, which is why many planners withdraw below 4%. See the financial disclaimer.
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The share of income kept, as a percentage: savings ÷ income × 100. It is the most predictive number in personal finance — at a 50% rate, financial independence is roughly 17 years away under typical assumptions, versus about 51 years at 10%.
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The risk that bad market years arrive early in retirement, damaging the portfolio exactly when withdrawals begin — the same average return can succeed or fail depending on its order. It is the reason early retirees use withdrawal rates below the classic 4% and hold cash buffers.
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Interest computed only on the original principal, never on accumulated interest: $10,000 at 7% simple earns $700 a year, every year. Most real borrowing and saving compounds instead — comparing the two side by side is the fastest way to see why compound interest dominates long horizons.
Money saved in advance for a known, upcoming expense — annual insurance, holidays, a car replacement — in its own bucket at a fixed amount per month. Unlike an emergency fund it is for the predictable; a planned bill that arrives “by surprise” is a budgeting bug, not bad luck.
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Costs that change with usage or timing — groceries, utilities, fuel, dining out. They are the flexible half of a budget and where month-to-month adjustments actually bite, which is why every line gets classified as fixed or variable before deciding what to cut.
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Assigning every dollar of income a job — expenses, savings, debt — until income minus assignments equals zero. Nothing is “left over” by design; unallocated money gets a job on purpose, which is what stops it from quietly evaporating.
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