Net Active Users is a KPI that can give you a pretty precise idea of your company’s growth trend very early in the game. It is calculated as follows:
Net Active Users = (New Users + Returning Users) - Churned Users.
Basically, not all your active users (new users + returning ones) are going to stick with your app and pay for your services. Some of them will abandon the product for various reasons and churn. And this is what the net active users metric shows you: how many users you can actually count on within a given time period.
When talking about the new users, it is important to count the number of on-boarded users in determining their number and not many sign-ups you have, since the number of sign-ups is prone to significant fluctuations which don’t automatically become paying customers.
Let me give you an example. This is how the graph for net active users looks like.