# Excel TRIMMEAN Function

The Excel TRIMMEAN function calculates mean (average) while excluding outliers. The number of data points to exclude is provided as a percentage.

**array**- Values to trim and average.**percent**- The number of data points to exclude from the calculation.

The Excel TRIMMEAN function calculates mean (average) while excluding outliers. The number of data points to exclude is provided as a percentage.

TRIMMEAN works by first excluding values from the top and bottom of a data set, then calculating mean. The number of data points is provided as a percentage. The percentage can be input either in decimal format or percent format:

It's important to note that TRIMMEAN rounds excluded data points down to the nearest multiple of 2. For example, with 50 data points, 10% equals 5 values. In this case, TRIMMEAN will round 5 down to 4, then exclude two values from the top, of the data set, and two values from the bottom of the data set.