The COUNTIF function in Excel is a handy trick when you are trying to get total counts of certain data types from a big data set. For example, you are tracking the lifespan of accounts in days and you want to see how many are 90 days or younger. Using the COUNTIF function, you can easily get a return total tally. The formula layout is COUNTIF(range, criteria). The example below is using a small scale data set however this formula is good if pulling from a large number of cells – like 100 or more.