BE-ACOS = (Gross) Margin (without PPC Costs) in past 90 Days
In order to calculate the Break-Even ACoS of all adgroups & campaigns, Sellics take the avarage margin (without PPC costs) of the respective products in the past 90 days.
The calculation is therefore:
Profit (without PPC costs) in past 90 days / Gross revenue within past 90 days