How to use the average view duration calculator
Average view duration in seconds and average percentage viewed are two different metrics. Duration is total watch time divided by views, an absolute length. Percentage viewed divides that length by the video length. Fifteen seconds of a 30-second cut and fifteen seconds of a ten-minute cut share the same duration but mean opposite things, so whenever lengths differ you need the percentage too.
Dashboards usually report watch time in minutes or hours, so you can pick the unit here. Whichever you choose, the math runs in seconds. The view count must come from the same video and the same period as the watch time.
Add the video length and you also get the average percentage viewed and how much of the video is left unwatched on average. The percentage divides the average duration shown on screen by the length, so you can check it by hand. Short videos that loop can exceed 100%, and the label says so when that happens. Platforms differ in how long a play must run to count as a view, which shifts duration as well, so calculate channel by channel rather than averaging channels together.
Frequently asked questions
Yes. When the same person replays a video, total watch time exceeds views times length. It is common on looping short-form video.
You can, but the result changes. Play starts include very short plays that never qualified as views, which drags the average duration down.