Calculating total differences and mark in red

[falcios]

How can I set up Excel to accurately highlight total differences. For example:

Total for December 2016 80
Total for January 2017 100
Total for February 2017 60

December and January is an increase of 20 but it shows as a negative
January & February is a decrease of 40 but it shows as a positive

I want to format it so that the if the total difference between two months is lower than mark it red. If the difference is higher, do nothing.

Thanks for your help.

 

[Eric W]

You can do that with custom formatting. Select the column with the value. From the Number group of the Home tab, click on the format box, choose "more formats" Then choose Number, then click on a red format on the right.