When working with Excel spreadsheets,we may be required to get the percentage difference between 2 numbers. Percentage difference is simply the difference between the original value and the new value, expressed as a percentage.
Formula to get percentage difference
We can calculate the percentage change in Excel using the formula below
% of Difference = (New Value – Old value)/Old value
When we calculate percentage difference with formula in Excel, the answer we get is simply in number format. Usually, we multiply the result with 100 in order to get the percentage difference in numbers. However, this is not the case when we are trying to find percentage difference between two numbers. Excel has a built-in feature that automatically formats the result into Excel percentage difference.
How the Excel difference formula works
When using the percentage difference formula to calculate the difference, it first starts by calculating the difference between the specified values. This is the actual change, where the original value is subtracted from the new value. After getting the diff, the result is divided by the original value, which is also referred to as the old value. We get a decimal value result.
For us to get the difference as a percentage, we have to format it using percentage number format first.
Examples of how to calculate percentage difference between two numbers in Excel
Example 1: Calculate percentage difference between two columns
Step 1: Prepare the data for which you want to find the percentage difference
Figure 1: Data to find difference
Step 2: Find the difference between two columns
Figure 2: Find the difference in numbers
Note how we find the difference in the above figure. All we need to do is subtract column B from A. in cell C2 for example, we have B2 – A2 to get 70 as the difference.
Step 3: Divide the difference with the original value
Figure 3: Calculate percentage difference between original and new value
It is also important to note that when finding difference, we can have a positive difference or a negative difference. The positive differences are called increases while the negative differences are called decreases. In our figure above, you will notice that cell C3 and cell C4 have negative differences, meaning the change is negative.
In column D, we have the results in column C divided by the original value, also referred to as the old value to get the decimal results.
Step 4: Format to get the decimal results into percentage change
To format the difference column into a percentage, we need to first highlight it. Then after highlighting it, we right-click anywhere in the column to start formatting.
Figure 4: Format to get the result as percentage change
In the dialog box that appears, choose numbers as your format type and the select percentage. Then click OK.
Figure 5: Select Percentage as the format
After clicking on OK, you will have all the differences converted to percentage as shown in the figure below:
Figure 6: Percentage difference
Perhaps, we should remember that we do not have a function for difference, thus we have to master how to use the difference formula to get changes between values.