How to calculate monthly active users
You've seen a brief overview of how MAU is calculated. Now let's take a closer look at the 2 steps involved.
Step 1: Define "active"
This step is important in determining just how useful your MAU measurement is. It can be something as simple as a user logging in. That may make sense for your product but likely will not give you a lot of information about whether the user actually used the product. A more useful definition would be a user that performs a specific action in your product. For example, if you have a product that converts image files from one format to another, an active user would be one that converts at least one image file. The less precise your definition of an active user is, the more fuzzy the data will be when MAU grows or shrinks.
Step 2: Measure the number of users that meet that definition over a given month
Once you've decided on a what an active user actually is, you need to measure how many of them log in within the period of a month. Here, it is important to remember that each user only counts once per month, as the goal is to measure only unique users. You can follow a similar method to get the number of daily or weekly active users as well.