CPM Calculator

What this calculator does

CPM, cost per thousand impressions (the M is the Roman numeral for a thousand), is how display ad pricing is usually quoted. This calculator links the three numbers that define a campaign, total cost, CPM rate, and impressions, and works out whichever one you leave out.

How to use it

1. Fill in exactly two of the three fields: Total Cost, CPM Rate, and Ad Impressions.
2. Leave the field you want to find empty.
3. Press Calculate, and the tool fills in the third. Reset clears all three.

The tool expects exactly two meaningful values, so if you fill in one or all three it will ask you to enter two.

How it works

All three numbers sit in a single relationship: CPM is the cost of every thousand impressions. From that one idea, the tool rearranges to solve for whichever value is missing:

• CPM = (Total Cost ÷ Impressions) × 1,000
• Total Cost = CPM × Impressions ÷ 1,000
• Impressions = (Total Cost ÷ CPM) × 1,000

The thousand appears in each line because CPM is priced per thousand impressions rather than per single impression.

A worked example

Suppose a campaign cost $50 and ran 20,000 impressions, and you want the CPM.

CPM = ($50 ÷ 20,000) × 1,000 = 0.0025 × 1,000 = $2.50. Every thousand impressions cost two and a half dollars.

It works in reverse too. At a $2.50 CPM over 20,000 impressions, Total Cost = 2.50 × 20,000 ÷ 1,000 = $50, which lands right back where we started.

What CPM is for

CPM is an impression-based price, so you are paying for your ad to be seen rather than clicked. That makes it the natural fit for awareness and branding, where the goal is reach: getting in front of as many of the right people as possible. If clicks and traffic are the goal instead, cost per click is the more telling number.

The two connect through your click-through rate. Once you know your CPM and CTR, the CPC calculator turns them into a cost per click, and on the publisher side the AdSense calculator estimates earnings from the same family of figures.

Questions people ask