Estimate data used for online courses.
Recorded lectures are usually encoded well below entertainment video — a talking head with slides at 720p needs only about 2-3 Mbps — so an hour costs roughly 1.1 GB rather than the 2.2 GB of a 1080p film. Course materials are trivial by comparison. Projecting across the full course length gives the figure that matters when deciding whether a mobile plan can carry a semester of study.
Course data over the term
GB per hour = Mbps x 3600 / (8 x 1024); video GB = GB per hour x weekly hours x weeks; total = video GB + materials MB x weeks / 1024
Yes, more than with entertainment video. Slide-based lectures remain fully legible at 480p, roughly a third of the 720p data, and playing at 1.5x speed cuts the bytes proportionally because less video is transferred.
Usually yes. A live session is a two-way video call, so your own outgoing stream adds to the incoming one — often 0.5-1.5 GB an hour in total against about 1.1 GB for watching a recording.
If the platform allows it and you rewatch, definitely. Revision viewing is where repeated streaming quietly doubles or triples the total for a course.