In the Attribute name field, enter a descriptive name to refer to the Real Time Calculated Attribute.
Select the appropriate Aggregation type using the drop-down menu. The values can be Count, Sum and Unique List.
In Select a field, choose the attribute on which the calculation works based on the chosen aggregation type.

In event(s) field, provide the event name(s). In the example shown below, the event name is Event OrderVal.
You can further specify conditions for your Calculated Attributes by clicking Add Condition. Note that you can also include Non-customer entity data in the conditions based on your requirement. 


