CPM Calculator

CPM formula

CPM means cost per mille, or cost per thousand impressions:

CPM = cost / impressions * 1000

If an ad placement costs $500 and delivers 100,000 impressions, the CPM is:

500 / 100,000 * 1,000 = 5

That means the campaign paid $5 for each block of 1,000 impressions.

Worked campaign example

Suppose a campaign spends $500, receives 100,000 impressions, earns 1,200 clicks, records 60 conversions and produces $900 in revenue.

The CPM alone says the media was bought cheaply or expensively per exposure. The CPC and CTR show whether those exposures created enough visits. CPA and ROAS show whether the clicks turned into business value.

CPM, CPC and CTR together

CPM and CPC are two views of the same spend. A CPM campaign can still have an effective CPC once clicks are known. A CPC campaign can still be expressed as an effective CPM once impressions are known. CTR links the two because it measures how often impressions become clicks.

For example, a $10 CPM with a 2% CTR implies about $0.50 per click: 1,000 impressions cost $10 and produce 20 clicks. If the same $10 CPM only has a 0.2% CTR, it produces 2 clicks and the effective CPC becomes $5.

Common pitfalls

• Mixing gross and net spend. Include platform fees, creative surcharges or agency fees only if you want CPM to reflect fully loaded cost.
• Counting the wrong impression definition. Served, viewable and billable impressions can differ by platform.
• Stopping at CPM. Awareness campaigns can optimize for reach, but performance campaigns also need CPC, CPA, ROAS and profit checks.
• Comparing unlike audiences. A narrow high-intent audience may carry a higher CPM and still be more efficient after conversion value.