Ad Viewability Rate Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026An impression served isn't always an impression seen
The Media Rating Council's widely adopted viewability standard requires at least 50% of an ad's pixels in view for a minimum of 1 continuous second (2 seconds for video) before it counts as genuinely viewable - many served impressions never meet this bar at all.
Worked example
For 75,000 viewable impressions out of 100,000 measured impressions:
Viewability = 75000 / 100000 x 100 = 75.0% (Meets the commonly cited IAB/MRC viewability standard)
Many media buyers now specifically target campaigns averaging 70% viewability or higher, and some contracts include viewability-based makegoods or refunds when campaigns fall meaningfully short of agreed thresholds.