Your Idle-Empire account has a certain level that is based on the amount of experience (XP) that you earn over time. There is no level limit.
XP can be earned by earning points and by completing achievements. You earn 1 XP for every point that you earn. Achievements can also give you quite a lot of XP.
You can see your current level and your current amount of XP when you visit your Idle-Empire user profile. In the Achievements tab you can also see all your completed and uncompleted achievements, as well as the number of XP that each achievement gives you.
Your account level does not have any impact on your earnings, it's just a visual feature. There are plans to add small features in the future that can only be accessed with a certain level.
Your level is calculated through the following function:
Accordingly, the following function is used to calculate your XP:
Here's a graph showing the correlation between level and XP: