# Average or Mean > This query is available as `average` and `mean`. An average is a single number taken as representative of a list of numbers. It is calculated as: ``` average = sum(numbers) / count(numbers) ``` ## how to use Use it in alerts like this: ``` alarm: my_alert on: my_chart lookup: average -1m unaligned of my_dimension warn: $this > 1000 ``` `average` does not change the units. For example, if the chart units is `requests/sec`, the result will be again expressed in the same units. It can also be used in APIs and badges as `&group=average` in the URL. ## Examples Examining last 1 minute `successful` web server responses: -  -  -  ## References - .