In this part of the formula, COUNTIF will return a positive number if any cell in the range is less than 65, and zero if not. In the range B5:F5, there is one score below 65 so COUNTIF will return 1. The NOT function is used to convert the number of from COUNTIF into a TRUE or FALSE result. The trick is that NOT also “flips” the result at the same time:

If any values are less than 65, COUNTIF returns a positive number and NOT returns FALSE f no values are less than 65, COUNTIF returns a zero and NOT returns TRUE

This is the equivalent of wrapping COUNTIF inside IF and providing a “reversed” TRUE and FALSE result like this:

Dave Bruns

Hi - I’m Dave Bruns, and I run Exceljet with my wife, Lisa. Our goal is to help you work faster in Excel. We create short videos, and clear examples of formulas, functions, pivot tables, conditional formatting, and charts.