WatchTime Calc is a free browser extension for Chrome and Firefox that automatically calculates total YouTube playlist lengths directly on YouTube.com. Instead of copying URLs into external tools, WatchTime Calc injects real-time duration badges, average video length, and custom speed calculators right beside YouTube playlists.
The YouTube Playlist Length Problem
When studying online courses, binge-watching tutorial series, or listening to music playlists on YouTube, the native interface displays the total number of videos but conceals total watch time. Students and self-learners often waste time manually summing up hours of video content.
What is WatchTime Calc?
WatchTime Calc seamlessly hooks into YouTube playlist header elements. Whenever you visit any playlist page, the extension automatically sums all video durations and presents total watch times at 1.0x, 1.25x, 1.5x, 1.75x, and 2.0x speeds.
Key Features & In-Page Integration
- Native UI Injection: Displays total duration directly beneath the playlist title on YouTube.
- Playback Speed Estimator: See instantly how much time you save watching at 1.25x, 1.5x, or 2.0x.
- Zero Data Tracking: Operates entirely client-side without storing user history or account credentials.
Frequently Asked Questions
Does WatchTime Calc work on unlisted playlists?
Yes. As long as you can open the playlist page on YouTube, WatchTime Calc can parse video durations.
Get WatchTime Calc Extension
Instantly see total YouTube playlist durations while browsing.
Get for Chrome →
Get for Firefox →