How do the Reach and Frequency metrics work on Facebook?

Do you have discrepancies when calculating Reach or Frequency totals in your Facebook queries?

It is possible that, if you sum the values of these metrics to get the total value, you will get something like this:

Sum in Google Sheets:

Results in Facebook Console:


As you can see these total results do not match. This is because Facebook (and Dataslayer) do not calculate the total by summing the individual data, but rather this amount is calculated separately.

Facebook calculates the total value of these metrics independently of how it calculates the individual values shown above in the table. In fact, if you sum the values shown in the Facebook console, you will notice that, as in Dataslayer, they do not match the total value of the metric.

Therefore, this is not a Dataslayer error, as we display the values returned by the Facebook API. It is a Facebook feature, that calculates this metric in 2 separate ways: on the one hand, the total, and on the other hand, the individual results when dimensions are added.

How do I solve it?

It's very simple. If you want to get the same total value that Facebook shows, don't sum the individual results. Instead, do the query without dimensions, as shown in the following image:

The same applies in the case of BigQuery. If you want to get the total results as Facebook calculates them, add a new table without dimensions, just don't sum the individual results.


As always, please do not hesitate to contact us via our live chat on our website or via e-mail if you still have doubts or questions. We are happy to help!