Divide each clip's duration by its playback speed
Convert the duration to minutes before dividing. A 45-minute lecture at 1.5× takes 30 minutes if it plays continuously. If you change speeds during the recording, split it at those timestamps, calculate each segment and add them. Subtract anything you actually plan to skip before estimating the total.
Add time for specific learning tasks
Identify where you need to pause, such as a proof or worked example. Give each stop a rough budget. If you are unsure, watch the first ten minutes, note how much wall-clock time passed, and use that as a check on the rest of the session.
Use timestamps when you run out of time
Choose the section that supports your next task, such as a problem set question. Note where its explanation starts and ends. With ten minutes left, save the next important timestamp and try one retrieval question instead of accelerating through a section you cannot work on yet.
Worked example
A recording contains 24 minutes of familiar material and 18 minutes of a new worked example. Play the first at 2× and the second at 1.25× for a total of 26 minutes and 24 seconds. Add eight minutes to attempt the example and five to recall the key steps. A 40-minute study slot leaves a little room for one rewind.
Before you finish
- Calculate each speed segment separately.
- Reserve time to stop and attempt an example.
- Save the exact timestamp for anything you defer.