Watch time
Also called watch hours · total watch time · 4,000 watch hours
The cumulative hours viewers have spent watching a channel's videos, the metric behind monetisation eligibility and much of YouTube's recommendation system.
In more detail
Watch time accumulates across every video on a channel rather than resetting per upload, which makes it a channel-level total rather than a per-video score. The YouTube Partner Program's standard eligibility bar is 1,000 subscribers and 4,000 public watch hours in the trailing 12 months, and YouTube's recommendation system is understood to weight watch time heavily alongside click-through rate and retention when deciding what to surface.
Example
A channel with four videos averaging 1,000 views and a 20-minute average view duration is contributing roughly 1,300 watch hours a month from that batch alone, which shows how quickly longer-form uploads move this number even at modest view counts.
Why it matters
Chasing views alone can leave a channel short of the watch-time threshold even after clearing the subscriber count, which is a common way a channel stalls just before monetisation. Formats that hold attention for longer, not just formats that get clicked more, are what actually move this number.