Glossary
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Clear, short definitions of the terms you will meet across our calculators.
- Amortization
- A repayment schedule that spreads a loan's principal and interest over equal periodic payments so the balance reaches zero at the end of the term.
- Annuity
- A series of equal payments made at regular intervals, such as the fixed monthly payments on a loan or a stream of regular deposits into an investment.
- APR (Annual Percentage Rate)
- The yearly cost of borrowing shown as a percentage, including interest and certain fees, which makes it easier to compare loan offers.
- APY (Annual Percentage Yield)
- The yearly rate of return on savings or an investment with compounding included, so it reflects interest earned on interest over a year.
- Average
- A single value that represents the center of a data set. In everyday use it usually means the mean, though the median and mode are also averages.
- BMI (Body Mass Index)
- A screening figure relating weight to height, calculated as weight in kilograms divided by height in metres squared.
- BMR (Basal Metabolic Rate)
- The number of calories the body uses at complete rest to maintain basic functions such as breathing and circulation.
- Body fat
- The share of total body weight made up of fat tissue, usually given as a percentage. It is a separate measure from BMI, which does not distinguish fat from muscle.
- Calorie
- A unit of energy used to measure the energy in food and the energy the body uses. On nutrition labels, one Calorie equals one kilocalorie.
- Compound interest
- Interest calculated on both the original principal and previously earned interest, causing a balance to grow faster over time.
- Compounding frequency
- How often interest is added to a balance, for example annually, monthly, or daily. More frequent compounding produces slightly higher growth.
- Denominator
- The bottom number in a fraction, which shows how many equal parts the whole is divided into. In three quarters, the denominator is four.
- Equity
- The share of an asset that an owner actually holds, after subtracting any debt against it. In ownership terms it is the owned portion of the total, often shown as a percentage.
- Future value
- What an amount of money is expected to be worth at a later date after growth from interest or investment returns is applied.
- Inflation
- The gradual rise in prices over time, which reduces how much a fixed amount of money can buy. It lowers the real value of future cash.
- Leap year
- A year with 366 days, adding February 29, that keeps the calendar aligned with the Earth's orbit. It occurs in most years divisible by four.
- Lean mass
- The weight of everything in the body that is not fat, including muscle, bone, organs, and water. It is the counterpart to body fat when body composition is split in two.
- Margin
- Profit shown as a share of the selling price: profit divided by sales, times 100. It differs from markup, which divides the same profit by cost instead.
- Mean
- The arithmetic average of a set of numbers: the sum of the values divided by how many values there are.
- Median
- The middle value of a sorted list of numbers. With an even count, it is the average of the two central values.
- Mode
- The value that appears most frequently in a data set. A set can have one mode, several, or none.
- Numerator
- The top number in a fraction, which shows how many equal parts are counted. In three quarters, the numerator is three.
- Percentage
- A way of expressing a number as a part of 100. The word means per hundred, so 25 percent is 25 out of every 100.
- Percentage point
- The plain difference between two percentages. A rise from 10 percent to 15 percent is 5 percentage points, though it is a 50 percent increase.
- Percentile
- A value below which a given share of a data set falls. Scoring in the 90th percentile means 90 percent of results are at or below yours.
- Principal
- The original amount of a loan or investment, before interest is applied.
- Range
- The difference between the largest and smallest values in a data set, indicating how spread out the values are.
- Ratio
- A comparison of two quantities that shows how much of one there is relative to the other, often written with a colon such as 3:1.
- Simple interest
- Interest calculated only on the original principal, not on interest already earned. It produces slower growth than compound interest.
- TDEE (Total Daily Energy Expenditure)
- An estimate of the total calories a person burns in a day, found by multiplying BMR by an activity factor.