The CPM formula is total cost divided by total impressions, multiplied by 1,000. A campaign that spent $1,500 and served 250,000 impressions ran at a $6.00 CPM: 1,500 ÷ 250,000 = 0.006, and 0.006 × 1,000 = 6.
CPM = (total cost ÷ total impressions) × 1,000
How to calculate CPM comes down to two inputs from one report: cost and impressions. Rearrange them to get impressions from a budget, sum them to blend campaigns, put them in a spreadsheet, or chain them to CPC and CPA. The last section adds the creative cost that most CPM maths leaves out.
The CPM formula, term by term
CPM stands for cost per mille, from the Latin for thousand, so it is the cost per thousand impressions. Google Ads defines it as a way to bid where you pay per one thousand views, and TikTok's bidding methods guide describes a CPM bid as the most you will pay for a thousand impressions.
- Total cost is what the ad account charged for the period, in one currency: media spend only, unless you want an all-in CPM (see the last section).
- Total impressions is the number of times the ad was served. It is not reach, which counts unique people: one person who sees an ad three times is three impressions.
- × 1,000 exists because one impression costs a fraction of a cent ($0.006 in the example above), which is hard to read or compare. Per thousand, it becomes a price buyers can quote and bid.
How to calculate CPM in three steps
Calculating CPM takes two numbers from one ad account report and one division.
- Add up the total cost. Take what the ad account charged for one date range, in one currency. For a standard CPM, count media spend only.
- Count the impressions for the same period. Use impressions, the number of times the ad was served, for exactly the same date range and campaigns. Do not use reach, which counts unique people.
- Divide the cost by the impressions and multiply by 1,000. Divide cost by impressions, then multiply by 1,000. $1,500 of spend on 250,000 impressions gives 1,500 ÷ 250,000 × 1,000, a $6.00 CPM.
Three mistakes break the result: dividing by reach, which is smaller than impressions and so overstates CPM; spend and impressions from different date ranges; and mixed currencies. Round only at the end.
Worked CPM examples
The inputs below are round example numbers that show the arithmetic, not benchmarks.
| Example | Cost | Impressions | Arithmetic | CPM |
|---|---|---|---|---|
| Small test | $75 | 9,400 | 75 ÷ 9,400 × 1,000 | $7.98 |
| Paid social flight | $1,500 | 250,000 | 1,500 ÷ 250,000 × 1,000 | $6.00 |
| Video campaign | $3,200 | 160,000 | 3,200 ÷ 160,000 × 1,000 | $20.00 |
| Display campaign | $900 | 600,000 | 900 ÷ 600,000 × 1,000 | $1.50 |
A $1.50 CPM and a $20.00 CPM can both be fine, because CPM prices attention, not results. The CPC and CPA section below shows how to judge one by what it produces.
Reverse the CPM formula: impressions or budget
Rearranged, the formula tells you what a budget buys and what an impression goal costs.
| You want | Formula | Example |
|---|---|---|
| CPM | cost ÷ impressions × 1,000 | $1,500 ÷ 250,000 × 1,000 = $6.00 |
| Impressions | budget ÷ CPM × 1,000 | $2,000 ÷ $8.00 × 1,000 = 250,000 |
| Budget | CPM × impressions ÷ 1,000 | $12.00 × 500,000 ÷ 1,000 = $6,000 |
How to calculate impressions from CPM
Divide the budget by the CPM, then multiply by 1,000. TikTok says an ad group's daily budget must exceed $20 per day (TikTok Ads Manager Help, Budget, July 2026).
At a TikTok CPM of $4.82 per 1,000 impressions (Gupta Media, Social CPM Tracker, Oct 2025), each $20 of daily budget buys about 4,149 impressions. Rerun it with your own account's CPM, and see TikTok CPM benchmarks and what pushes them up for why that figure moves.
How to calculate a budget from a target CPM
Multiply the CPM by the impressions you want and divide by 1,000. The CPM you plug in matters more than the arithmetic, because published figures for one platform disagree.
One million Meta impressions cost $8,190 at $8.19 per 1,000 impressions (Gupta Media, Social CPM Tracker, Oct 2025) but $15,060 at $15.06 per 1,000 impressions (Triple Whale, via Fibbler, Sep 2026). Switch to your own account's CPM once you have one.
Blended CPM across campaigns
To calculate CPM across several campaigns, add up all the spend, add up all the impressions and run the formula once. Never average the individual CPMs: a simple average gives a small campaign the same weight as a large one.
| Campaign | Spend | Impressions | CPM |
|---|---|---|---|
| A | $1,000 | 200,000 | $5.00 |
| B | $1,000 | 50,000 | $20.00 |
| Average of the two CPMs (wrong) | $12.50 | ||
| Blended: $2,000 ÷ 250,000 × 1,000 | $2,000 | 250,000 | $8.00 |
The $12.50 average overstates the real $8.00 by more than half, because campaign B bought a fifth of the impressions but counts for half the average.
CPM formula in Excel and Google Sheets
Put spend in column B and impressions in column C, starting on row 2. The same formulas work in Excel and Google Sheets.
| Result | Formula |
|---|---|
| CPM for one row | =B2/C2*1000 |
| CPM rounded to cents | =ROUND(B2/C2*1000,2) |
| CPM that skips rows with no impressions | =IF(C2=0,"",B2/C2*1000) |
| Blended CPM for rows 2 to 50 | =SUM(B2:B50)/SUM(C2:C50)*1000 |
| Impressions from a budget (E2) and a CPM (F2) | =E2/F2*1000 |
| Budget from a CPM (F2) and target impressions (G2) | =F2*G2/1000 |
A result a thousand times too small means the *1000 is missing; one far too high usually means
column C holds reach or clicks.
From CPM to CPC and CPA
Click-through rate and conversion rate turn CPM into the cost of a click and of a customer. The identities are exact, so they work in either direction.
| Metric | Formula (rates as decimals, 1% = 0.01) |
|---|---|
| CPC from CPM | CPM ÷ (1,000 × CTR) |
| CPA from CPM | CPM ÷ (1,000 × CTR × conversion rate) |
| CPM from CPC | CPC × CTR × 1,000 |
Example inputs: a $10.00 CPM, a 1% CTR and a 2% conversion rate. CPC is 10 ÷ (1,000 × 0.01) = $1.00, and CPA is 10 ÷ (1,000 × 0.01 × 0.02) = $50.00. So every $10 buys 1,000 impressions, 10 clicks and 0.2 conversions.
Because CPA moves with CPM divided by CTR, halving your CPM and doubling your CTR each halve your CPA. That is why a cheap CPM on an ad nobody clicks is not a bargain. The free ad metrics calculator runs this chain forwards from your account numbers and backwards from a budget.
Run the chain on your own numbers. Published CPM, CTR and conversion figures are medians or averages over different accounts, so multiplying one source's CPM by another's CTR gives nobody's real CPA.
CPM vs eCPM, vCPM and oCPM
The formula stays the same; what changes is which impressions count and how you are billed.
| Term | Formula | Where you meet it |
|---|---|---|
| CPM | cost ÷ impressions × 1,000 | A bid type and a reporting metric (Google Ads, TikTok and others) |
| eCPM (effective CPM) | cost or earnings ÷ impressions × 1,000, whatever the pricing model | Comparing CPC or CPV buys with CPM buys after the fact; publisher earnings |
| vCPM (viewable CPM) | cost ÷ viewable impressions × 1,000 | Google Ads display and video campaigns |
| oCPM (optimized CPM) | cost ÷ impressions × 1,000, billed per impression | TikTok conversion, lead generation and app install objectives |
Google Ads counts an ad as viewable when 50 percent of it shows on screen for 1 second or longer for display ads, or when it plays continuously for 2 seconds or longer for video ads, per its viewable CPM help page. Fewer impressions qualify, so the same spend gives a higher vCPM than CPM.
On TikTok, an oCPM bid buys a thousand impressions shown to people likely to take the action you chose, and it is the default for the conversions and app install objectives, per the bidding methods guide (last updated August 2025). You are still charged by impression, so the CPM formula applies to the spend unchanged.
Sanity-check your result against published CPMs
None of the major ad platforms we checked publishes its own average CPM, so every figure below is third-party, with its own sample and period. Use them to catch a calculation error, not as a target.
| Benchmark | Value | Scope | Source |
|---|---|---|---|
| Meta CPM, 2025 average | $8.19 per 1,000 impressions | Meta (Facebook + Instagram) · Not stated by the source · Multi-industry · 2025 (average as of Oct 2025) The source's October 2025 monthly figures are internally inconsistent, so only its 2025 average is used. | Gupta Media, Social CPM Tracker Oct 2025 · dataset |
| Meta CPM, ecommerce median | $15.06 per 1,000 impressions | Meta (Facebook + Instagram) · Ecommerce · Aug 2025–Jul 2026 Triple Whale data as summarized by Fibbler. | Triple Whale, via Fibbler Sep 2026 · aggregator |
| TikTok CPM, 2025 average | $4.82 per 1,000 impressions | TikTok · Not stated by the source · Multi-industry · 2025 (average as of Oct 2025) | Gupta Media, Social CPM Tracker Oct 2025 · dataset |
| YouTube CPM, 2025 average | $4.99 per 1,000 impressions | YouTube · Not stated by the source · Multi-industry · 2025 (average as of Oct 2025) | Gupta Media, Social CPM Tracker Oct 2025 · dataset |
Third-party benchmarks as published by each source; sources checked 2026-09-30. Ranges vary by industry, audience and period, so treat them as context rather than targets.
The two Meta rows show why one number misleads: an average across mostly US advertisers in 2025 against a median for ecommerce brands from August 2025 to July 2026. For how to judge the number you get, see what counts as a good CPM by platform and by the cost per acquisition it implies.
All-in CPM: the creative cost the formula leaves out
Ad platforms report media CPM, what the auction charged. The creative that ran in those impressions was paid for separately, and all-in CPM puts it back: (media spend + creative spend) ÷ impressions × 1,000.
A worked all-in example
Example inputs: $3,000 of media delivering 400,000 impressions, a media CPM of $7.50. The creative is 5 short-form videos from human creators at Billo's market average of $200 per video (Billo, UGC Rates, 2026-06-16), so $1,000 before usage rights.
All-in CPM is ($3,000 + $1,000) ÷ 400,000 × 1,000 = $10.00, 33% above what the ad account reports. Billo notes that licensing can double or triple creator costs, so the real gap is often wider.
Testing volume multiplies the creative line
TikTok's creative best practices page, last updated June 2025, implies 9 to 25 distinct creatives per campaign at launch (three to five ad groups, each carrying three to five creatives). At a per-video rate, every one of them adds to the numerator of all-in CPM.
A plan price as the creative line
With AI video, the creative line becomes a plan price rather than a per-video fee. Playcut's paid plans run from $9 a month to $149 per seat a month; Pro is $29 a month with 2,000 credits, and credit packs of 600 credits for $9, 2,500 for $35 and 5,000 for $65 never expire.
Credits are spent per generation. In Playcut's Act step, which turns a script into a clip of a saved AI actor speaking it, a 10-second 720p clip costs 85 credits on the default tier (7 a second plus a 15-credit scene step), so Pro's 2,000 credits cover 23. The default Veo 3.1 model runs 160 credits a second at 720p, 1,280 for 8 seconds.
So the plan price enters the all-in formula as a flat line that does not rise with each variant until the credits run out. See the AI UGC ad generator for the actor workflow, and AI-actor video ads for TikTok or Facebook and Instagram video ad creative for each placement.
What this does not claim
Nothing here shows that AI creative lowers your CPM. TikTok says its auction ranks ads on bid price and relevance, so creative can affect delivery, but no source we checked puts a reliable number on it. Rerolls cost credits too, and the full cost stack of an AI video ad counts them.
AI actors present a product; they must not pose as real customers describing their own experience. See the FTC rules for AI UGC ads.