Playback Time Calculator | YouTube, Udemy

This extension displays time by playback speed of videos and playlists. Features: Displays the time by playback speed of video. Displays the total playing time of the playlist(by playback speed). How to use: ⏱: Time is displayed by playback speed when you mouse over it. Caution: If there are more than 100 videos in the playlist, scroll down and it will be counted again when loading is complete. - youtube