Where the channel health score comes from
The health score out of 100 is four fundamentals scored out of 25 each from the channel's most recent uploads, every one measured against that channel's own history.
Four pillars, 25 each
Upload consistency, engagement, momentum and reach. The page explains each one in plain words before you run it.
Engagement is a median
Likes and comments as a share of views, taken as a median so one viral outlier cannot flatter the result. The target is 5 percent.
Momentum is the early warning
The newest uploads against the ones before them. When recent videos underperform older ones, the cause is usually the packaging, not the content.
The same score in Lens
On the channel page, Lens shows the same four pillars with their bars, and the biggest lever with the measured reason behind it.
Why it works this way
Every pillar is measured against the channel's own history, so the score tells you what to change on this channel, not how far you are from someone else's.