Free tool

CPM Calculator

CPM is what you pay for a thousand ad impressions: ad spend divided by impressions, times 1,000. Pick the number you’re solving for, enter the other two, and copy the matching Google Sheets formula for your report. The math is the easy part. Comparing CPMs is where people go wrong, because Meta and Google don’t count an impression the same way.

Solve for
CPM
$6.25

$2,500.00 ÷ 400,000 impressions × 1,000 = $6.25 per 1,000 impressions

Ad spend in column B, impressions in column C.

What’s a good CPM?

One that’s lower than your own past campaigns on the same platform, chasing the same goal. Google’s own help page makes the point: CPM is most valuable as a comparison between ads, ad groups and campaigns, not as an isolated number. So compare your result with the same campaign last month, or another ad set in the same account.

A higher CPM isn’t automatically worse. If the pricier audience clicks and buys more often, your cost per result can still come out lower, so read CPM next to what the money got you.

You won’t find an average CPM table here, on purpose. Two other CPM calculator pages put Facebook’s average CPM at $19.84 and at $7 to $10, and neither says where its number comes from or when it was measured. If they can’t agree, neither one is your benchmark.

The CPM formula, three ways

CPM stands for cost per mille. Mille is Latin for thousand, as Microsoft’s ad glossary puts it. The math is the same on every platform:

  • CPM = ad spend ÷ impressions × 1,000
  • Ad spend = CPM × impressions ÷ 1,000
  • Impressions = ad spend ÷ CPM × 1,000

Meta’s own example: $50 for 10,000 impressions is a $5 CPM.

One formula, three ways roundAd spend sits on top. Impressions divided by 1,000 and CPM sit underneath. Ad spend of $2,500 divided by 400 thousand-impressions gives a CPM of $6.25. CPM times thousand-impressions gives the ad spend. Ad spend divided by CPM gives the thousands of impressions.Ad spend$2,500Impressions ÷ 1,000400,000 ÷ 1,000 = 400CPM$6.25
Cover the number you want. If it’s the top one, multiply the two bottom ones. If it’s a bottom one, divide the top by the other bottom one. So $2,500 ÷ $6.25 gives 400, which is 400 thousand impressions.

Why CPMs from different platforms don’t line up

Every platform does the same division, but each one decides for itself what counts as an impression.

  • Meta counts an impression the first time an ad is on screen. A video doesn’t have to start playing for it to count, except on Meta Audience Network.
  • Google Ads counts an impression each time your ad is shown, and that’s what Avg. CPM divides by. Avg. viewable CPM only counts viewable impressions: at least half the ad on screen for one second, or a video playing for two seconds straight. Viewable CPM bidding is for Display Network campaigns.
  • Microsoft Advertising’s manual CPM, on Audience campaigns, charges per 1,000 viewed impressions: more than half the ad in view for at least a second, or two seconds of video.

Google’s viewability rule is the one in the Media Rating Council’s viewable impression guideline: at least 50% of the ad’s pixels in view for one continuous second, two for video. So a $6 Avg. viewable CPM and a $6 Meta CPM don’t buy the same thing: one only counts ads that stayed at least half in view. Compare Meta with Meta, and Google’s Avg. CPM with Avg. CPM.

What counts as one impression
  • Meta (Facebook, Instagram)
    CPM
    The ad is on screen for the first time
  • Google Ads
    Avg. CPM
    The ad is shown
  • Google Ads
    Avg. viewable CPM
    50% of the ad on screen for 1 second (video: plays 2 seconds)
  • Microsoft Advertising
    Manual CPM
    More than 50% in view for 1 second (video: 2 seconds)
The filled share is how much of the ad has to be in view.

A worked example

Say you run two Facebook ad sets for a client in October. Ad set A spent $2,500 for 400,000 impressions, a $6.25 CPM. Ad set B spent $1,800 for 240,000 impressions, a $7.50 CPM. B costs more per impression, so check its clicks and conversions before you move budget away from it.

Next month the client wants 1,000,000 impressions. At ad set A’s CPM that’s $6,250 (switch the calculator to Ad spend). And $1,000 on B buys about 133,333 impressions at $7.50 (switch to Impressions).

Calculate CPM in Google Sheets

Put ad spend in column B and impressions in column C, then type this in D2:

=IFERROR(ROUND(B2/C2*1000, 2), "")

ROUND keeps it to cents. IFERROR returns an empty cell instead of an error, so a row with no impressions yet stays blank. It hides other errors too, so check any row that comes back empty. Drag the formula down and every campaign row gets its CPM. The calculator above shows the formula for whichever number you solve for. Using Excel? Paste in the same formula: Excel’s IFERROR and ROUND work the same way.

Typing spend and impressions into a sheet every week is the slow part. SyncWith pulls them straight from your ad accounts into Google Sheets and refreshes them on a schedule you pick, from every 5 minutes to monthly. Facebook Ads is the source our users connect most, at 51% of attributed new connections across SyncWith’s Google Sheets add-on and Looker Studio connectors in Q3 2026. Facebook Ads reports can include Spend, Impressions and Facebook’s own CPM. Google Ads reports bring in Cost and Impressions, and the formula above turns them into a CPM. LinkedIn Ads, TikTok Ads and Microsoft Ads connect the same way.

The free Hobby plan includes 35 report refreshes a month, and paid plans start at $24.99 a month. See Google Sheets pricing.

Get spend and impressions into Google Sheets automatically

Install it free, connect your ad accounts, and pick how often the sheet refreshes. No credit card needed.

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Questions

What does a $20 CPM mean?

You’re paying $20 for every thousand impressions, or 2 cents each. So $500 buys 25,000 impressions, and 100,000 impressions cost $2,000.

What’s the difference between CPM, CPC and CPA?

They divide the same spend by different things. CPM is the cost per thousand impressions. CPC is the cost per click. CPA is the cost per action. In Google Ads, a Target CPA is the average cost per conversion you want. CPM prices getting seen; CPC and CPA price the response.

What’s the difference between CPM and vCPM?

CPM divides spend by every impression counted. vCPM, viewable CPM, divides it by viewable impressions only, the ones that were at least half on screen for a second (two seconds for video). Fewer impressions qualify for the same spend, so a campaign’s vCPM comes out at or above its CPM.

To cite this calculator: SyncWith CPM Calculator, https://syncwith.com/tools/cpm-calculator. Platform definitions checked October 17, 2026.