# Calculator glossary 34 terms · Updated 18 October 2026 by Adrian Viziteu The words behind everyday sums, explained in a few lines each, with the exact line to type into Ratio and the answer it gives. ## Money and tax VAT, margins, interest and loans, the way you would type them. - [**VAT (value-added tax)**](https://useratio.app/glossary/vat): A consumption tax added to the price of goods and services. Each country sets its own rate. - [**Gross and net price**](https://useratio.app/glossary/gross-and-net): Net is the price before tax. Gross is the price with tax included. - [**Margin**](https://useratio.app/glossary/margin): Profit as a share of the selling price. - [**Markup**](https://useratio.app/glossary/markup): Profit as a share of the cost. - [**Percentage change**](https://useratio.app/glossary/percentage-change): How much a number grew or shrank, as a percent of where it started. - [**Compound interest**](https://useratio.app/glossary/compound-interest): Interest that is earned on the interest as well as on the original amount. - [**Loan payment (PMT)**](https://useratio.app/glossary/loan-payment): The fixed amount you pay each period to repay a loan with interest. - [**Net present value (NPV)**](https://useratio.app/glossary/npv): Today's value of money you will receive later, given a discount rate. - [**Internal rate of return (IRR)**](https://useratio.app/glossary/irr): The discount rate at which the net present value of a series of cash flows is zero. - [**Exchange rate**](https://useratio.app/glossary/exchange-rate): How much of one currency you get for one unit of another. ## Dates and time Working days, time zones and countdowns. - [**Working days**](https://useratio.app/glossary/working-days): Business days: the days of the week that are not weekends or public holidays. - [**Time zone**](https://useratio.app/glossary/time-zone): A region that keeps the same clock time, set as an offset from UTC. - [**Unix timestamp**](https://useratio.app/glossary/unix-timestamp): The number of seconds since 1 January 1970, 00:00 UTC. - [**Countdown**](https://useratio.app/glossary/countdown): The time left until a moment in the future. ## Units and data Conversions that trip people up. - [**GB and GiB**](https://useratio.app/glossary/gb-vs-gib): GB counts in thousands. GiB counts in 1,024s. - [**Celsius and Fahrenheit**](https://useratio.app/glossary/celsius-fahrenheit): Two temperature scales. Water freezes at 0 °C and 32 °F. - [**Aspect ratio**](https://useratio.app/glossary/aspect-ratio): The proportion of an image or screen, width to height. - [**Uptime and downtime**](https://useratio.app/glossary/uptime): The share of time a service is available, and the time it is not. ## Maths and statistics From percentages to equations. - [**Median and mean**](https://useratio.app/glossary/median): The mean adds the numbers and divides by how many there are. The median is the middle number once they are sorted. - [**Standard deviation**](https://useratio.app/glossary/standard-deviation): A measure of how spread out a set of numbers is around their mean. - [**Percentile**](https://useratio.app/glossary/percentile): The value below which a given share of the data falls. - [**Prime number**](https://useratio.app/glossary/prime-number): A whole number greater than 1 that only divides by 1 and itself. - [**Complex number**](https://useratio.app/glossary/complex-number): A number with a real part and an imaginary part, written like 3 + 4i. - [**Derivative and integral**](https://useratio.app/glossary/derivative-and-integral): The derivative is the rate of change at a point. The definite integral is the area under a curve between two points. - [**Quadratic equation**](https://useratio.app/glossary/quadratic-equation): An equation where the unknown is squared, like x² − 5x + 6 = 0. ## Developer terms Hex, binary, permissions and colours. - [**Hexadecimal**](https://useratio.app/glossary/hexadecimal): Counting in base 16, with the digits 0 to 9 and A to F. - [**Binary**](https://useratio.app/glossary/binary): Counting in base 2, with only the digits 0 and 1. - [**Fixed-width integers (u8, i64)**](https://useratio.app/glossary/fixed-width-integer): Whole numbers stored in a set number of bits. u8 is unsigned 8-bit, i64 is signed 64-bit. - [**Bitwise operators**](https://useratio.app/glossary/bitwise): Operations that work on the individual bits of integers: AND, OR, XOR, NOT and shifts. - [**chmod permissions**](https://useratio.app/glossary/chmod): The Unix command that sets who can read, write and execute a file. - [**RGB and HSL colours**](https://useratio.app/glossary/rgb-and-hsl): Two ways of describing a colour: by its red, green and blue parts, or by hue, saturation and lightness. ## Notepad calculating The ideas behind a calculator that reads text. - [**Notepad calculator**](https://useratio.app/glossary/notepad-calculator): A calculator you type into like a note, with the answer shown beside each line. - [**Line reference**](https://useratio.app/glossary/line-reference): A way to use the result of another line in a calculation. - [**Variable**](https://useratio.app/glossary/variable): A name for a value, so you can reuse it. Not sure where to start? Read [what a notepad calculator is](https://useratio.app/what-is-a-notepad-calculator) or see everything Ratio understands in [Syntax and examples](https://useratio.app/docs). [Try Ratio free for 7 days](https://useratio.app/download) Source: https://useratio.app/glossary