Free tool CPM calculator and CPM formula
CPM is what you pay for a thousand ad impressions. Enter any two of cost, impressions and CPM and the calculator works out the third, so you can compare channels or size a budget before you buy.
- Any two of three values
- Updates as you type
- Runs locally
Work out CPM, cost or impressions
Leave one box empty and the calculator solves for it. If all three are filled, CPM is recalculated from cost and impressions.
Total spend for the period, in your currency.
How many times the ad was shown.
Cost per 1,000 impressions. Leave empty to calculate it.
CPM (cost per 1,000 impressions)
$4.17
Divide spend by impressions and multiply by 1,000.
Share these inputs: the values go after the # in the link, so they never reach a server.
https://tapcub.com/tools/cpm-calculator
Version v1.0Updated Update history
What the number tells you, and what it does not
CPM measures how expensive attention is on a channel. It says nothing on its own about whether that attention turns into visits or sales.
CPM
The price of reach. Use it to compare placements that sell impressions, such as display, video and social feeds, on the same basis.
Solved budget
Enter a target CPM and the impressions you need, and the calculator returns the spend. Useful when a platform quotes a CPM and you plan a flight.
Solved impressions
Enter a budget and a CPM to see how many impressions it buys. Platforms charge by auction, so treat the result as an estimate.
CPM is not efficiency
A cheap CPM with no clicks costs more per customer than an expensive one that converts. Follow it with CTR, CPC and CPA before judging a channel.
Platforms differ in what counts as an impression (served, viewable, a minimum time on screen). Compare CPMs only within the same definition.
Three ways to use the calculator
The same formula answers three planning questions.
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1
Check a campaign
Enter spend and impressions from your ad report to get the CPM you actually paid.
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2
Size a budget
Enter the impressions you need and the CPM you expect; leave spend empty.
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3
Estimate reach
Enter a budget and a CPM; leave impressions empty to see what it buys.
CPM = spend ÷ impressions × 1,000
The "M" is the Roman numeral for a thousand (mille). The same relation rearranges to give spend or impressions.
- Use the same period and the same campaign for spend and impressions
- Use the currency the platform billed in; convert afterwards if needed
- Viewable CPM (vCPM) divides by viewable impressions instead, so it is higher
CPM
CPM = spend ÷ impressions × 1,000
Spend $5,000 on 1,200,000 impressions → CPM ≈ $4.17
Spend
spend = impressions × CPM ÷ 1,000
1,250,000 impressions at a $4.00 CPM → $5,000
Impressions
impressions = spend ÷ CPM × 1,000
$5,000 at a $4.00 CPM → 1,250,000 impressions
Same budget, three channels
A $5,000 monthly test split across three placements. CPM shows where attention is cheapest; the last column shows why that is only half the story.
| Channel | Spend | Impressions | CPM | Clicks |
|---|---|---|---|---|
| Display network | $2,000 | 800,000 | $2.50 | 640 |
| Social feed | $2,000 | 400,000 | $5.00 | 2,800 |
| Video pre-roll | $1,000 | 100,000 | $10.00 | 300 |
Display has the cheapest CPM but the social feed brings more than four times the clicks for the same spend: $0.71 per click against $3.13. Sample figures.
Where CPM comparisons go wrong
The arithmetic is simple. The traps are in what goes into it.
Mismatched periods
Spend from the monthly invoice and impressions from a weekly export give a CPM that describes nothing.
Mixing impression definitions
Served impressions and viewable impressions are different counts. A vCPM always looks more expensive than a CPM.
Optimising for CPM alone
The cheapest inventory is often the least seen. Judge channels on cost per click or per customer as well.
Comparing across currencies
A CPM in one currency and a CPM in another are not comparable until converted at the same rate.
From impressions to customers
CPM stops at the ad. TapCub picks up at the visit: it reads UTM parameters and ad click IDs, keeps the source on the visitor, and reports conversions and revenue per campaign.
Campaign and channel reports
Sessions, conversions and conversion rate per campaign, source and medium.
Learn moreChannel ROI
Import spend and see return per channel next to the traffic it bought.
Learn moreFirst and last touch
The campaign that introduced a customer and the one that closed, on the same person.
Learn moreCPM questions
Still have a question?
Chat with the team behind TapCub — we usually reply within a few hours on business days.
What does CPM stand for?
Cost per mille: the cost of one thousand impressions. "Mille" is Latin for thousand. Some platforms label it "cost per 1,000 impressions".
How do I calculate CPM?
The CPM formula is CPM = spend ÷ impressions × 1,000: divide total spend by total impressions and multiply by 1,000. $5,000 for 1,200,000 impressions is a CPM of about $4.17.
How is CPM different from CPC?
CPM is the price of a thousand impressions; CPC is the price of one click. If you know CTR, CPC = CPM ÷ (1,000 × CTR). The ad metrics calculator converts between them.
What is a good CPM?
It depends on the platform, the audience, the format and the season, so a single benchmark is misleading. Compare against your own past campaigns on the same platform, and judge the result on cost per customer, not CPM alone.
What is viewable CPM (vCPM)?
The cost per thousand impressions that met a viewability standard, such as half of the ad on screen for at least one second. Because fewer impressions qualify, vCPM is higher than CPM for the same spend.
Why does the CPM in my ad account differ from this result?
Usually the inputs: the account may report a different date range, exclude invalid traffic, or bill in another currency. Use spend and impressions from the same report.
Update history
New features, fixes and data refreshes for this tool, newest first.
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· v1.0
LaunchedFirst release.
Missing something or found an error? Tell us — requests that come up often go into the next update. All tool updates
See what the impressions turned into
Connect your site and every tagged campaign shows visits, conversions and revenue beside its cost.