Ad revenue per thousand impressions (RPM) is calculated by dividing your estimated earnings by the number of ad impressions you received, then multiplying by 1000.
Ad RPM = (Estimated earnings / Ad impressions) * 1000
For example, if you earned an estimated $180 from 45,000 ad impressions, your ad RPM would equal ($180 / 45,000) * 1000, or $4.00.
Note: This metric is only available under the "Advanced" metric family tab. Learn more about picking metrics for your report.