CPM (Cost Per Mille) Calculator

CPM is the price of one thousand ad impressions: total spend divided by impressions, times a thousand. It is how display, video and connected-TV inventory is quoted, and the three quantities (spend, impressions, CPM) form a triangle where any two give you the third. This calculator solves for whichever one you leave out.

Beyond the bare figure, in Solve for CPM mode it answers the planning question a CPM alone does not: to reach a lower target CPM, how many more impressions you would need at the current spend, or how much less you could spend at the current impression count. Nothing is sent to an ad platform.

Getting a Number Out of the Triangle

1. Pick what to Solve for: CPM, Impressions, or Total spend. The two fields you are not solving for become the inputs.
2. Enter the two known values. Load Sample fills a Meta feed campaign of $4,200 spend over 560,000 impressions, which works out to a $7.50 CPM.
3. In Solve for CPM mode, optionally set a Target CPM. The sample’s target of 6.50 shows the gap: 86,154 more impressions at the same spend, or $560 less spend at the same impressions.
4. Read the Derived Figures panel for cost per single impression and impressions per $1,000, and press Copy to grab the headline number without its currency symbol.

The Three Forms of the CPM Formula

• CPM = spend ÷ impressions × 1,000. The sample: 4,200 ÷ 560,000 × 1,000 = 7.50.
• Impressions = spend ÷ CPM × 1,000. A $4,200 budget at a $7.50 CPM buys 560,000 impressions.
• Total spend = CPM × impressions ÷ 1,000. 560,000 impressions at a $7.50 CPM costs $4,200.
• Cost per single impression is spend ÷ impressions with no thousand multiplier, so $0.0075 for the sample, and impressions per $1,000 is the inverse scaled up, 133,333.

What This Rounds and Where It Stops

• Currency figures show two decimal places, or four when the value is under $1, so a sub-dollar cost per impression stays readable rather than collapsing to $0.01.
• Impression counts are rounded to whole numbers, because you cannot buy a fraction of an impression, and the “more impressions needed” figure is rounded up, never down.
• A dollar sign, commas and spaces are stripped from every field before parsing, so $4,200 and 4200 are read the same. A zero or negative in a required field is treated as not yet filled; a bad Target CPM stops with “Target CPM must be a positive number.”
• The target-gap section only appears in Solve for CPM mode, and only when the target is below the current CPM. A target at or above it shows “Already at or below the target CPM” instead, because for CPM lower is cheaper.
• The channel benchmark ranges are published rules of thumb, not a live rate card. Your own account reporting is the only figure that settles a media plan.