Cost per thousand impressions, or CPM, expresses advertising cost per 1,000 impressions. Google Ads uses CPM terminology for impression-based advertising. Its guidance distinguishes viewable CPM, so check the exact reporting label before comparing figures. Source: Google Ads: Cost-per-thousand impressions definition

Put the number in context

For a worked example, £150 spent on 30,000 impressions gives a CPM of £5: divide the spend by impressions, then multiply by 1,000. State the reporting period and placement with the number. This keeps the calculation traceable when the figures are shared with colleagues.

Keep the campaign purpose clear

If the campaign is intended to introduce a travel brand, write down how that aim will be reviewed before launch. Show any enquiry results separately. Do not describe impressions as bookings or named people reached, because the calculation here contains only spend and recorded impressions. This avoids asking one measure to answer several different questions.

Written and updated by Travelgenix. Sources checked on 16 October 2026. Worked examples and recommendations are editorial illustrations, not customer results.