Determining the average of two percentages is similar to calculating the average of any two numbers. You add the two numbers and divide them by two. For simplicity, you may convert the two percentage values into decimals before dividing them by two to calculate the average. Multiply the resulting value by 100 if you need the answer as a percentage.
First, convert the two percentages into decimals. For example, suppose you want to calculate the average of 60 percent and 40 percent. Convert these values into decimals by dividing them by 100, so you get 0.6 and 0.4.
Secondly, find the sum of the two decimal values. In this example, adding 0.6 and 0.4 gives you 1.
Thirdly, divide the resulting value by 2. In this example, 1/2 = 0.5.
Finally, multiply the answer by 100 to get the answer in percentage. Multiplying 0.5 by 100 gives you 50 percent.
TL;DR (Too Long; Didn't Read)
Another method is to take the percentage out and determine the average of the two numbers as you regularly would. The resulting value will express the average of the two percentages. So you could solve same example as (60 + 40)/2 percent, which is equal to 50 percent.