# How are rates calculated?

May 8, 2016

Rates are calculating by dividing mathematically two quantities.

#### Explanation:

Mathematically speaking, any rate will respect the formula:

$r a t e = \frac{\Delta x}{\Delta y}$, where $x$ and $y$ are arbitrary variables, generally uncorrelated, e.g space and time.

In a more advanced notation, using calculus:

$r a t e = \frac{\mathrm{dx}}{\mathrm{dy}} = x '$, which means the derivative of $x$.

So, to calculate a rate, you must have two values changing, you fix a time, or any equivalent measure, and calculate their changes, then divide them. Your rate will tell you how the numerator variable changes with the denominator variable.

Examples are: velocity - how space changes with time; acceleration - how the velocity changes with time. See that most rates, not necessary mandatory, will be something with respect time.

Some rates

See for more: Rate (mathematics)