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): A consumption tax added to the price of goods and services. Each country sets its own rate.
Gross and net price: Net is the price before tax. Gross is the price with tax included.
Margin: Profit as a share of the selling price.
Markup: Profit as a share of the cost.
Percentage change: How much a number grew or shrank, as a percent of where it started.
Compound interest: Interest that is earned on the interest as well as on the original amount.
Loan payment (PMT): The fixed amount you pay each period to repay a loan with interest.
Net present value (NPV): Today's value of money you will receive later, given a discount rate.
Internal rate of return (IRR): The discount rate at which the net present value of a series of cash flows is zero.
Exchange rate: How much of one currency you get for one unit of another.

Working days, time zones and countdowns.

Working days: Business days: the days of the week that are not weekends or public holidays.
Time zone: A region that keeps the same clock time, set as an offset from UTC.
Unix timestamp: The number of seconds since 1 January 1970, 00:00 UTC.
Countdown: The time left until a moment in the future.

Conversions that trip people up.

GB and GiB: GB counts in thousands. GiB counts in 1,024s.
Celsius and Fahrenheit: Two temperature scales. Water freezes at 0 °C and 32 °F.
Aspect ratio: The proportion of an image or screen, width to height.
Uptime and downtime: The share of time a service is available, and the time it is not.

From percentages to equations.

Median and mean: The mean adds the numbers and divides by how many there are. The median is the middle number once they are sorted.
Standard deviation: A measure of how spread out a set of numbers is around their mean.
Percentile: The value below which a given share of the data falls.
Prime number: A whole number greater than 1 that only divides by 1 and itself.
Complex number: A number with a real part and an imaginary part, written like 3 + 4i.
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: An equation where the unknown is squared, like x² − 5x + 6 = 0.

Hex, binary, permissions and colours.

Hexadecimal: Counting in base 16, with the digits 0 to 9 and A to F.
Binary: Counting in base 2, with only the digits 0 and 1.
Fixed-width integers (u8, i64): Whole numbers stored in a set number of bits. u8 is unsigned 8-bit, i64 is signed 64-bit.
Bitwise operators: Operations that work on the individual bits of integers: AND, OR, XOR, NOT and shifts.
chmod permissions: The Unix command that sets who can read, write and execute a file.
RGB and HSL colours: Two ways of describing a colour: by its red, green and blue parts, or by hue, saturation and lightness.

The ideas behind a calculator that reads text.

Notepad calculator: A calculator you type into like a note, with the answer shown beside each line.
Line reference: A way to use the result of another line in a calculation.
Variable: A name for a value, so you can reuse it.

Not sure where to start? Read what a notepad calculator is or see everything Ratio understands in Syntax and examples.