How much bandwidth does a standard TV channel use?

Standard OTA (Over the air) television channels are able to use about 19.3Mbps. If it's a channel that has several sub-channels for example 38.1 or 38.2 then they have to divide the 19.3Mbps up between the sub-channels.

Generally speaking channels that are standard definition use anywhere from 4Mbps-7Mbps. High definition channels generally use anywhere from 10-15Mbps.

When dealing with content that is on cable/Satellite though things change because different content providers compress each network different amounts.