# Percent of Change

## Key Questions

• The percentage change formula is:

$\left({X}_{2} / {X}_{1} - 1\right) \cdot 100$

where ${X}_{1}$ is the original value and ${X}_{2}$ is the final value.

Example:

If Google's stock price increases from $500 to$575, it has increased by 15%.

(575 / 500 - 1) * 100 = 15%

See the process below:

#### Explanation:

The formula for calculating the percent change in a value between two points in time is:

p% = (N - O)/O * 100

Where:

$p$ is the percent change

$N$ is the New Value.

$O$ is the Old Value

Take the old and new values you are given in the problem, substitute them for $O$ and $N$ and calculate the percent change

• The formula for calculating the percent change in a value between two points in time is:

$p = \frac{N - O}{O} \cdot 100$

Where:

$p$ is the percent change

$N$ is the New Value

$O$ is the Old Value

• If $x$ is some changing quantity, and $\Delta x$ be the change in $x$-value, then the percentage change can be found by

$\frac{\Delta x}{x} \times 100$

Example

What is the percentage change (discount) of $12 discount on$300 item?

{12}/{300} times 100=4% discount

I hope that this was helpful.