Estimate monthly mobile data usage from habits.
Mobile data usage is dominated by video, so an estimate built from viewing hours and bitrate is far more accurate than a general guess. Audio is included at a typical 160 kbps and turns out to be almost negligible by comparison — around 70 MB an hour against video's 2 GB. Everything else is entered as a monthly lump because browsing, messaging and app updates are hard to decompose and small in aggregate.
Usage estimate by activity
Video GB = Mbps x 3600 / (8 x 1024) x weekly hours x 4.35; audio GB = 160 kbps equivalent x weekly hours x 4.35; total = video + audio + other; recommended = total x 1.25
Roughly 0.7 Mbps for 480p, 3 Mbps for 720p, 5 Mbps for 1080p and 16-18 Mbps for 4K. Social video autoplay usually sits around 1-2 Mbps because of aggressive adaptive encoding.
Because usage is not uniform. A holiday week, a large app update or a few days without wifi can push a month well above average, and the cost of an overage typically exceeds the cost of a slightly larger plan.
Not for a mobile plan. Enter only the hours you expect to spend on cellular data. For a home broadband estimate, include everything.