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CPM (Cost Per Mille) Calculator

From ad cost and impressions, compute the cost per 1,000 impressions (CPM).

Input Data

Cost
HK$
Impressions
times

Results

Cost / impressions x 1,000.
HK$6.25

At a glance:CPM = ad cost / impressions x 1,000 — the cost to show the ad 1,000 times. It benchmarks reach campaigns (display, video, OOH). Lower CPM = cheaper reach, but it only measures reach cost, not clicks or conversions. Pair with CPC/CTR/CPA. WARNING: low CPM with imprecise/bot traffic is wasted; compare on viewability and conversion, not just price. Education, not advice.

Formula

CPM = cost / impressions × 1,000.

$$CPM = \dfrac{\text{Cost}}{\text{Impressions}} \times 1000$$

How to Use

  1. Enter the total ad spend.
  2. Enter total impressions.
  3. View the cost per 1,000 impressions (CPM).

FAQ

What is the difference between CPM and CPC?

CPM prices per 1,000 impressions (reach/awareness); CPC prices per click (traffic/conversion). One campaign can show both: CPM for reach cost, CPC for traffic efficiency.

Is lower CPM always better?

Not necessarily. Low CPM means cheap reach, but if the audience is imprecise, impressions are invalid/bot, or the ad is not viewable, it is wasted. Judge with viewability, audience fit and final click/conversion.

How do I compare media using CPM?

Plug each channel's spend and impressions into the formula to get its CPM, then compare on the uniform 'per thousand impressions' basis. Ensure impressions are defined consistently (e.g. viewable) and weigh audience fit and conversion too.

What is an impression / viewable impression?

An impression is one ad load/serve — counted even if the user never scrolled to see it. Viewable impressions (per IAB/MRC) require ≥50% of the ad visible for ≥1 second (video often ≥2s), filtering 'seen' from 'served'. vCPM prices on viewable impressions. The impressions you enter should state which definition is used.

Does low CPM mean the ad is worthwhile?

No — low CPM only means cheap reach, not effectiveness or profit. Down the funnel, low CPM with terrible CTR yields high effective CPC; low conversion yields high CPA. Real goal is acceptable CPA/ROAS, not the lowest CPM. Sometimes paying higher CPM for precise, quality reach is cheaper overall. Use CTR and CPA calculators to diagnose the whole funnel.

Related Tools

References

Content review: Calculatorism Finance Team. Results are for reference only; please refer to the relevant authorities for the official figures.

Found a problem with the results?

If this calculator's result is wrong, or you have any question about the calculation logic, please let us know. You are viewing:CPM (Cost Per Mille) Calculator（/finance/cpm）。