Viewable CPM Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026Paying for what's actually seen, not just served
Standard CPM divides spend by all served impressions, but vCPM divides by viewable impressions only - a more honest picture of the real cost per genuinely visible ad, filtering out impressions served below the fold or to an inactive browser tab.
Worked example
For $500 in ad spend generating 75,000 viewable impressions:
vCPM = (500 / 75000) x 1000 = 6.667 vCPM
Notice vCPM is always higher than standard CPM calculated on the same spend, since the viewable impression count is always smaller than or equal to total served impressions - the gap between the two figures reveals exactly how much an advertiser is paying for impressions that were never actually visible.