## Percentage Change

**What Is Percentage Change?**

Percentage change can be applied to any quantity. Let’s say you are tracking the the grow of height. If the height increased, use the formula

**(New Height – Old Height)/Old Height **

**Then, multiply that number by 100%. **

If the price decreased, use the formula

**(Old Height – New Height)/Old Height **

**Then multiply that number by 100%. **

This formula is used both to track the height of someone / something.

Percentage change show the degree of change

Percentage change can be used for any quantity

Positive values show a percentage increase whereas negative values show percentage decrease.

Table of Contents

## Definition of Change

To find a change, subtract old value from new value.

You had 4 pens, but now have 7.

The change is: 7-4 = 3.

## Definition of Percentage Change

Percentage change is a concept of mathematics that represents the degree of change over time. There are many purposes to use this in finance, for ecample: to represent the price change in supermarket.

Percentage change shows the change as a percent of the old value.

To find the percentage change divide by the old value and make it a percentage:

So the percentage change from 4 to 7 is:

3/4 = 0.75 = 75%

## How to find percentage change

There are 2 ways to calculate a percentage change, use the one you prefer:

**Method 1**

- subtract old value from the new value
- divide that change by the old value
- multiply by 100 and adding a “%” sign

Note:

when the new value is greater then the old value, it is a percentage increase, otherwise it is a decrease.

### Method 2

- divide the New Value by the Old Value
- multiply by 100 and adding a “%” sign
- subtract 100% from that

Note:

when the result is positive it is a percentage increase, if negative, just remove the minus sign and call it a decrease.

A Bag went from $5 to $10, what is the percentage change?

**Method 1:**

Step 1: $10 – $5 = $5 change

Step 2: $5/$5 = 1

Step 3: 1×100 = 100% rise.

That means a 100% rise.

**Method 2:**

Step 1: $10/$5 = 2

Step 2: 2×100 = 200%

Step 3: 200% – 100% = 100%

Same result with method 1

## Formula

To calculate a percentage change, use this formula

**Change = New Number – Original Number**

Next, divide the change by the original number and multiply the result by 100%:

**% change = change ÷ Original Number × 100%.**

If the answer is a positive number, then the percentage change is increase.

If the answer is a negative number, then the percentage change is a decrease.

**Other Formula**

You can also put the values into this formula:

(The “|” symbols mean absolute value, so negatives become positive)

There were 100 apples yesterday, and 120 today:

A 20% increase.