Cost per thousand impressions and supporting figures
Choose the quantity to solve, then enter the other two values. CPM scales cost per impression to a thousand displays. Solved impressions can be fractional estimates; entered impression counts must be whole numbers.
After estimating exposure cost, the ROI Calculator can compare actual proceeds and costs for a separate return measure.
The formula
Choose the quantity to solve, then enter the other two values. CPM scales cost per impression to a thousand displays. Solved impressions can be fractional estimates; entered impression counts must be whole numbers.
Worked cpm example
Spending 500 for 100,000 impressions produces CPM of 5. In budget mode, CPM of 5 and 250,000 impressions require 1,250. In impressions mode, spending 1,000 at CPM of 5 buys an estimated 200,000 displays.
How to use this calculator
- Choose whether to calculate CPM, advertising budget, or impression count.
- Enter the two visible quantities. Use a positive impression count when solving CPM and a positive CPM when solving impressions.
- Calculate to compare cost per thousand displays, total budget, and expected impressions; changing the mode updates the required controls.
Choosing inputs for cpm
CPM is a unit-cost measure, regardless of whether the campaign is billed by impression, click, or another method. Dividing total advertising spend by delivered impressions makes campaigns comparable on exposure cost, provided their cost definitions and impression-counting rules are consistent.
A thousand impressions can come from many people seeing a message once or a smaller audience seeing it repeatedly. CPM does not describe unique reach, frequency, or viewability. A viewable CPM uses a different denominator, so do not substitute ordinary impressions when comparing a vCPM report.
Interpreting cost per thousand impressions
Choose CPM mode to measure observed media cost, budget mode to price an impression target, or impressions mode to estimate delivery from a budget. The estimates hold average unit cost constant. Larger purchases may encounter different inventory, placements, audiences, and auction prices, so these arithmetic scenarios do not guarantee delivery. A solved fractional impression count is an expected amount, while an actual reported impression count is a whole number.
Assumptions & limitations
What this calculation assumes
- Entered impression counts are whole numbers; solved counts are expected amounts.
- Average impression cost stays constant in budget and delivery scenarios.
What to keep in mind
- Unique reach, viewable impressions, auction changes, click rates, and advertising revenue are excluded.
Common questions
Does the M mean million?
In CPM it refers to one thousand, so the cost is scaled per 1,000 impressions.
Is CPM the same as vCPM?
No. Viewable CPM uses viewable impressions; this calculator uses the impression denominator you enter.
How do I solve for impressions?
Choose impressions mode, enter advertising spend and a positive CPM, then calculate the expected number of displays.
Sources & further reading
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