Enter the average and the value of one of the numbers into the Reverse Average Calculator. The calculator will evaluate and display the value of the unknown number.

Reverse Average Formula

The following formula is used to calculate the Reverse Average. 

V1 = 2*AV-V2
  • Where V1 is the missing number value
  • AV is the average 
  • V1 is the value of the known number value

To calculate an initial value from an average, multiply the average by 2, then subtract the final/second value.

How to Calculate Reverse Average?

The following example problems outline how to calculate Reverse Average.

Example Problem #1:

  1. First, determine the average.
    • The average is given as: 30.
  2. Next, determine the value of one of the numbers.
    • The value of one of the numbers is provided as: 20.
  3. Finally, calculate the Reverse Average using the equation above: 

V1 = 2*AV-V2

The values given above are inserted into the equation below and the solution is calculated:

V1 = 2*30-20 = 40

Example Problem #2: 

For this problem, the variables required are provided below:

average = 40

value of one of the numbers = 10

Test your knowledge using the equation and check your answer with the calculator above.

V1 = 2*AV-V2 = ?