CPM Calculator
Work out CPM, the cost to reach one thousand ad impressions, or reverse-solve for the ad spend or impressions you need. Switch modes, add audience size for reach and frequency, layer in a click-through rate for clicks and CPC, then benchmark the result against typical platform CPMs.
Formula
Worked example
$500 spent for 200,000 impressions: 500 ÷ 200,000 = $0.0025 per impression, × 1,000 = a CPM of $2.50. Reversed, a $500 budget at a $5 CPM buys 1,000 × 500 ÷ 5 = 100,000 impressions.
What CPM measures
CPM stands for cost per mille, where "mille" is Latin for one thousand. It is the price an advertiser pays for one thousand ad impressions, where an impression is a single instance of the ad being served or displayed. Because impression counts run into the millions, quoting cost per thousand keeps the numbers readable. To calculate it, divide your total ad spend by the number of impressions, then multiply by 1,000. CPM is the standard pricing unit for display, video, and programmatic advertising where the goal is reach and visibility.
Reverse-solving: spend and impressions
CPM ties three numbers together, so knowing any two gives you the third. Use the "Solve for" selector to flip the calculator into the mode you need. Solve for ad spend when a publisher quotes you a CPM and you know how many impressions you want: spend equals CPM times impressions divided by 1,000. Solve for impressions when you have a fixed budget and a target CPM and want to know how much reach it buys: impressions equals 1,000 times spend divided by CPM. This is the same algebra rearranged, which is why planners use one CPM figure to price a buy, forecast delivery, and compare vendors.
Reach, frequency, clicks and CPC
Impressions count every time the ad is shown, but the same person can be served it many times. Turn on reach and frequency to enter the number of unique people reached: average frequency is impressions divided by reach, and cost per person reached is spend divided by reach. A frequency of three to five is often a healthy exposure level, while very high frequency can signal wasted budget or audience fatigue. Turn on the clicks option to add a click-through rate (CTR); estimated clicks are impressions times the CTR, and cost per click is spend divided by clicks. These extra outputs connect a pure reach metric to the actions that follow.
Using CPM to compare campaigns
A lower CPM means you pay less to put your ad in front of a thousand people, which lets a fixed budget reach more of an audience. But CPM only prices exposure, it does not tell you whether anyone clicked, signed up, or bought. A high-quality placement on a premium site may carry a higher CPM yet deliver a better return than cheap, untargeted inventory. Read CPM alongside click-through rate, cost per click, and conversion rate to understand whether inexpensive reach is translating into business results rather than just impressions. The benchmark table below gives rough platform averages to sanity-check your figure.
Typical CPM by platform
| Platform | Typical CPM | Notes |
|---|---|---|
| $6 - $9 | Premium B2B audiences lift the floor | |
| Twitter / X | $6 - $7 | Varies widely by objective |
| $7 - $12 | Auction-driven, rises in Q4 | |
| $7 - $9 | Feed and Stories priced together | |
| YouTube | $9 - $12 | Video views command higher CPMs |
| up to ~$30 | Niche, intent-led inventory | |
| Programmatic display | $1 - $5 | Cheap reach, lower attention |
Rough industry averages for orientation only; your CPM varies with targeting, format, season and bidding.
Frequently asked questions
How do you calculate CPM?
Divide your total ad spend by the number of impressions, then multiply by 1,000. For example, $500 spent across 200,000 impressions gives a CPM of (500 ÷ 200,000) × 1,000 = $2.50.
Can this calculator solve for spend or impressions instead of CPM?
Yes. Use the "Solve for" selector. Choose "Ad spend" to find the cost of a campaign from a quoted CPM and impression target, or "Impressions" to see how many impressions a fixed budget buys at a given CPM. It is the same CPM formula rearranged.
What is the difference between impressions, reach and frequency?
Impressions count every time the ad is displayed, including repeats to the same person. Reach is the number of unique people who saw it at least once. Frequency is impressions divided by reach, the average number of times each person was exposed. Turn on the reach option to see frequency and cost per person reached.
What is a good CPM?
It depends heavily on platform, audience, and format. Broad programmatic display can run a few dollars per thousand, while narrowly targeted social or video placements can be $10, $30 or more. Compare CPM against similar campaigns and the platform benchmark table rather than a single universal number.
Is a lower CPM always better?
Not necessarily. A low CPM stretches your reach, but cheap impressions are worthless if they miss your target audience or never convert. Evaluate CPM together with click-through and conversion rates to judge true value.