Estimate data used by smart home devices.
Individual smart home devices are almost trivially light — a smart plug or sensor sends a few megabytes a day of state and heartbeat traffic — but they multiply, and hubs and voice assistants are far chattier because they maintain persistent cloud connections and upload audio snippets. Firmware updates are the lumpy component: infrequent but tens or hundreds of megabytes when they land across a fleet of devices.
Fleet telemetry plus firmware
Daily MB = devices x MB per device + hub MB; monthly MB = daily x 30 + firmware MB; monthly GB = monthly MB / 1024
Anything carrying audio or video: doorbells, cameras and voice assistants dominate. Sensors, plugs, bulbs and thermostats are typically under 10 MB a day each, so a large fleet of them still totals very little.
It varies. Local protocols like Zigbee, Z-Wave, Thread and Matter can operate through a local hub with no cloud, while cloud-only devices become unresponsive. That distinction matters for reliability as much as for data.
On broadband, no — a typical smart home is a couple of gigabytes a month. It matters when the home runs on a metered cellular connection, where the always-on nature of the traffic gives no opportunity to defer it.