CPM Calculator
Calculate your CPM (cost per 1,000 ad impressions) from total spend and impressions delivered — the standard way to price and compare display, video, social, and CTV inventory before you know a single click or conversion happened.
Fees last verified: 2026-08-02
Your numbers
Results update instantly as you type.
The total amount spent on the ad campaign.
Total number of times the ad was shown.
CPM
$5.00
Cost per 1,000 impressions.
Cost per 100 impressions
$0.50
How the CPM Calculator works
Enter your total ad spend and the number of impressions the campaign delivered or is projected to deliver. The calculator divides spend by impressions and multiplies by 1,000 for CPM, plus shows cost per 100 impressions as a smaller-scale reference. Two common mistakes: mixing agency fees or platform markup into spend without labeling it, which distorts the result into neither a clean gross nor net figure; and mismatching impression definitions — served vs. viewable — against whatever number you're comparing this against elsewhere. Run the same campaign through the calculator at different points in a flight to see whether CPM is trending up or down, rather than treating one snapshot as the full picture.
Who this is for
For anyone buying, planning, or reporting on ad spend priced by impressions rather than by click or conversion. Media buyers use it to sanity-check a platform's quoted rate against what a campaign is actually delivering once live. Agencies use it to turn a raw 'we spent $X for Y impressions' export into a single client-facing number on awareness or reach reports. In-house marketers use it before a campaign launches, to forecast how many impressions a given display, social, or CTV budget will realistically buy at a target CPM. And anyone comparing reach across channels uses it to normalize wildly different spend and impression totals into one comparable unit.
Worked example
You spend $500 on a campaign that delivers 100,000 impressions. CPM = (500 / 100,000) × 1,000 = $5.00 — you're paying $5 for every 1,000 times your ad is shown, regardless of clicks. Cost per 100 impressions = $0.50. That $5.00 only tells you the cost of exposure. If this campaign's ads were clicked 800 times (a 0.8% CTR), effective cost per click works out to CPM ÷ (CTR × 1,000) = 5.00 / (0.008 × 1,000) = $0.625. A $5.00 CPM sitting on a weak CTR can end up costing more per click than an $8.00 CPM paired with a much stronger one — CPM alone never tells you which scenario you're in.
What CPM does and doesn't tell you
CPM measures one thing: the cost of delivering 1,000 impressions. It says nothing about whether those impressions were seen by an engaged person or whether the campaign produced a click or sale — the right lens for comparing raw cost of reach, the wrong lens for judging whether a campaign worked. CPM connects to the rest of the funnel through effective CPC = CPM ÷ (CTR × 1,000) — cost per click is really CPM divided by how well the creative and targeting convert impressions into clicks, so a higher CPM with a strong CTR can out-perform a cheaper CPM with a weak one. Cost per acquisition goes further still, folding in conversion rate on top of that. Judging a campaign on CPM alone is one of the most common ways a media plan looks efficient on a summary slide and isn't. CPM also varies structurally by channel, even without pinning to exact figures that shift by quarter and market. Static display/banner inventory is generally the most abundant and least targeted, which tends to make it cheapest per impression. Social feed placements sit in a more competitive auction, since many advertisers bid for overlapping audiences at once, typically pushing CPM higher than generic display. Video and CTV inventory usually commands a further premium — the format itself is more limited in supply, and CTV in particular is well known industry-wide for running meaningfully higher CPMs than display or feed placements. Treat these as directional patterns, not fixed numbers — actual CPM still swings heavily by audience specificity, seasonality, and geography. Two pitfalls worth flagging: 'served' and 'viewable' impressions (per the ad industry's MRC/IAB viewability standard) aren't the same denominator, so a CPM calculated against one isn't directly comparable to one calculated against the other. And a CPM that looks unusually cheap relative to everything else you're running is worth investigating, not celebrating — it can just as easily mean low-quality placements or invalid traffic as a genuinely efficient buy.
Frequently asked questions
What is CPM?
CPM stands for 'cost per mille' (mille is Latin for thousand) — what you pay for every 1,000 times an ad is served. It's the pricing unit behind most display, video, social, and CTV inventory, whether or not anyone clicks, because you're buying exposure, not action.
What's the formula for CPM?
CPM = (Total spend ÷ Impressions) × 1,000. Spend $500 and get 100,000 impressions, and CPM = (500 / 100,000) × 1,000 = $5.00. It also works backward: impressions = (Spend ÷ CPM) × 1,000, useful for forecasting reach from a budget before a campaign even launches.
What's a good CPM?
There's no single answer — CPM is driven by format (banner vs. video vs. CTV), platform competition, audience specificity, seasonality, and geography, all shifting constantly. A CPM that's great for a broad-reach display campaign would be alarmingly cheap — often a sign of low-quality or unviewable inventory — for a tightly targeted B2B audience competing for a much smaller pool of eligible viewers. The only reliable benchmark is your own account's history for that specific platform, format, and audience, tracked over time.
How is CPM different from CPC and CPA?
The three bill at different funnel stages. CPM charges per impression regardless of engagement — best for awareness. CPC (cost per click) only charges once someone clicks. CPA (cost per acquisition) only counts an actual sale, lead, or sign-up. They're linked: effective CPC = CPM ÷ (CTR × 1,000), so cost per click is really CPM divided by how well the creative converts impressions into clicks — a high CPM with a strong CTR can beat a cheap CPM with a weak one.
Does a low CPM always mean I'm getting a good deal?
No — a suspiciously cheap CPM can reflect low-quality inventory, poor placement, bot or invalid traffic inflating the impression count, or an audience too broad to realistically convert. CPM only measures cost of exposure, not whether it was seen by a real person in a viewable position. Read it alongside CTR at minimum, conversion rate ideally, before calling a cheap campaign efficient.
Why can two platforms report different CPMs for what looks like the same reach?
Usually because they're counting different things. A 'served' impression means the ad was technically delivered; a 'viewable' impression means it actually rendered somewhere a person could plausibly see it, per the ad industry's MRC/IAB viewability standard. Some platforms report against served impressions, others against viewable ones, and the same campaign can show a meaningfully different CPM depending on which denominator is used — confirm both sides use the same definition before comparing.
What mistakes do people make calculating or comparing CPM?
Mixing gross spend (agency fees, platform markup) with net media spend in one CPM figure without labeling which is which — a gross and net CPM for the identical campaign can differ meaningfully. Blending impressions across multiple placements or audiences into one average, which hides that one placement is performing well and another badly. And benchmarking against a generic, country-agnostic 'average CPM' pulled from an online source — ad markets vary enormously by country and platform, so an imported benchmark routinely produces the wrong conclusion.
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