Browser Extension
Instant YouTube Playlist Length & Speed Breakdown
Stop copying playlist URLs into third-party sites. WatchTime Calc injects real-time total duration badges and speed watchtimes (1.25x, 1.5x, 1.75x, 2.0x) directly into YouTube playlist headers.
✓ In-Page YouTube Integration
✓ 1.25x / 1.5x / 1.75x / 2.0x Speeds
✓ Zero Data Sent to Servers
Watch-Time Calculation Simulator
Simulate how WatchTime Calc computes duration breakdowns for custom playlists.
1.0x (NORMAL)
7h 12m
1.25x SPEED
5h 45m
1.5x SPEED
4h 48m
2.0x SPEED
3h 36m
Why Use WatchTime Calc?
Native Header Injection
Adds duration statistics seamlessly next to YouTube's native playlist details. Looks and feels like a native YouTube feature.
Plan Study Sprints
Instantly see whether you can finish a 50-video coding tutorial before the weekend by watching at 1.5x speed.
100% Privacy Preserved
Reads timestamps directly from your visible DOM elements. Zero YouTube API tokens needed, zero history tracked.
Frequently Asked Questions
Do I need to sign in with a Google account?
No. WatchTime Calc never asks for permissions to your Google account or YouTube channel. It works completely anonymously on public pages.
Does it handle very long playlists with 100+ videos?
Yes. It dynamically counts and accumulates durations as you scroll or load infinite playlist pages.