The ad value is calculated by taking the estimated post reach and an average price for online advertisement into account (CPM).
It shows how much you had to spend with common online ads (outside from Facebook) to get as much as reach as you got on Facebook with the selected posts / time period. We use an estimated CPM of 12.00 € and multiply it with the estimated reach.
The ad value does NOT show the amount you’ve spent on Facebook into ads.
Note: You can set your own CPM for different post types if you’re the admin of a page and granted us insight rights. The Ad Value does not proportionally depend on the number of fans, but more important is the engagement.