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