1. Open your Internet browser and access the AdSense website. Use your login and password to enter your account to collect the necessary data needed for the calculation. Under the 'Overview' tab, locate the section called 'AdSense for Content' and look to the right. The number to the right represents the information for your entire account. If you click on the clickable text link labeled, 'Top Channels,' this will show you the top advertisement channels (websites) which are making you money. Note down the number of page impressions under the 'Page impressions' header, along with the earnings under the 'Estimated Earnings.'
2. Compare revenue across different channels and advertising programs. Effective cost-per-thousand impressions (eCPM) is a useful way of doing this. Essentially, effective CPM represents your estimated earnings for every 1,000 impressions you receive. You may use the averages of your entire AdSense account, or the numbers from a specific channel, depending on your needs.
3. Divide your earning by the page impressions and multiply that amount by a 1,000 to get your eCPM. If you have estimated earnings of $90 and 20,000 page impressions, the eCPM would amount to -- ($90 / 20,000) * 1,000 -- or $4.50.