Percent Difference Formula
The percent difference formula of any two numbers is the absolute value of the ratio of their difference and their average multiplied by 100. The percent difference formula is used to find the percent difference of any two numbers. Let’s learn more about percentage difference, percent difference formula, percent difference equation, and how to calculate the difference.
What is Percent Difference Formula?
Percentage change between two numbers (or) percent change between two numbers is the ratio of their difference and the initial value multiplied by 100. When final value > initial value, the formula leads to a positive value which indicates a "percent increase.". When the final value < initial value, the formula leads to a negative value which indicates a "percent decrease." The percent difference formula of two numbers:
Percent Difference = Difference / Average × 100%
We can understand the steps to find the percentage difference of two numbers using the following flowchart.

Example 1: The height of a tower is increased from 30 ft to 50 ft. Find the percent difference using the percent difference formula.
Solution:
To find: The percentage difference between the heights of the given tower.
The initial height is, a = 30 ft.
The final height is, b = 50 ft.
The percent difference is calculated using the formula of percent difference:
\(
\left \dfrac{ab}{ \left(\dfrac{a+b}{2} \right)} \right\times 100\%\\[0.2cm]
=\left \dfrac{3050}{ \left(\dfrac{30+50}{2} \right)}\right \times 100\%\\[0.2cm]
= \left\dfrac{20}{ 40} \right \times 100\%\\[0.2cm]
=50\%
\)Answer: The percentage difference = 50%.

Example 2: Mia wrote 53 instead of writing 35. Find the percent difference between the numbers 35 and 53.
Solution:
To find: The percent difference between the numbers 35 and 53.
The given two numbers are:
a = 35 and b = 53.
The percent difference is calculated using the formula of percent difference:
\(\left \dfrac{ab}{ \left(\dfrac{a+b}{2} \right)} \right\times 100\%\\[0.2cm]
=\left \dfrac{3553}{ \left(\dfrac{35+53}{2} \right)}\right \times 100\%\\[0.2cm]
= \left\dfrac{18}{ 44} \right \times 100\%\\[0.2cm]
\approx 41\%\)Answer: The percentage difference = 41%.