How to calculate VTR
Divide counted video views by video ad impressions and multiply by 100. If an ad records 1,250 views from 10,000 impressions, VTR is 12.5%. YouTube calls this TrueView view rate; its view criteria depend on ad format. A counted view is not necessarily a completed video or a unique viewer.
Read the result in context
This is a video view rate, not a view-through conversion rate or ad viewability rate. View and impression criteria differ across platforms and video formats. Use counts from the same campaign, format, and reporting period. The percentage is a descriptive measure, not a guarantee of a conversion or business outcome.