How this is worked out
- Watching a camera from outside uses the upload speed at the camera site, not the download speed. Indian broadband often gives far less upload than download — check the plan.
- A phone app normally pulls the sub-stream, which is a small picture at about 0.5–1 Mbps. Full-screen or playback pulls the main stream, which is the same bitrate the camera records at.
- Each person watching needs their own copy of the stream, so two people watching four cameras is eight streams.
- Headroom is added because a link that is 100% full drops frames. 30% spare is the usual allowance.
- Data use is bitrate × time: 1 Mbps for an hour is about 0.45 GB.
An estimate for planning, not a design document. Site conditions change the answer — send it to us and we will confirm it free of charge.