The percentage difference is the difference between two values divided by the average of the two values expressed as a percentage.

**Formula to calculate percentage difference.**

- We begin by finding the difference of the two values.
- Then workout the average of the two values.
- Divide the difference by the average and then multiply the result by 100.

**Example:**

If presented with two values 50 and 70, calculate their percentage difference.

- Lets begin by finding their difference.

- Then we work out their average.

- Finally, we divide the difference by the average and then multiply the result by 100.

Therefore, the percentage difference of the two values is 33.3%.