Video Completion Rate Calculator: How Many Viewers Watch to the End

A video completion rate calculator divides how many people watched a video ad all the way through by how many times it started, so you can see whether your creative actually holds attention once someone presses play or the ad begins auto-playing.

How to calculate video completion rate

Divide completed views by video starts, then multiply by 100. If a video started 10,000 times and 6,500 of those viewers watched to the end, the completion rate is 6,500 divided by 10,000, times 100, which is 65 percent. The remaining 35 percent dropped off somewhere before the final frame.

What counts as a completed view

Ad platforms are not consistent about what goes in the denominator. Some report video starts, others report impressions, and a few only count views that passed a minimum viewability threshold. Before you compare completion rate across platforms or campaigns, check which definition each report is using, because a small difference in the denominator can move the percentage by several points without your creative actually performing any differently.

Video completion rate versus view rate

Completion rate and view rate answer different questions. View rate, calculated as views divided by impressions, tells you whether people chose to press play at all. Completion rate, calculated as completed views divided by starts, tells you whether the people who did press play stuck around. A video can have a strong view rate and a weak completion rate if the hook works but the middle drags, or the reverse if a plain thumbnail undersells a video that holds attention well once it starts. Run both numbers side by side with our video view rate calculator to see the full picture.