# How do you calculate the percent change of 64 to 80?

##### 2 Answers

Jun 6, 2017

First we need to know the difference between them:

Now we need this difference as a percentage:

#### Explanation:

We divide by 64 because we want to know how much the number has changed from its original value.

We multiply by 100 because 'per cent' means 'how many out of 100'.

Jun 6, 2017

See a solution process below:

#### Explanation:

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

Where:

Substituting and solving for

The percentage change between 64 and 80 is a 25% increase.