BBC iPlayer is a free service, but mobile network operators may charge for data used over their networks.
Data allowances and mobile network tariffs are the responsibility of the mobile network operators. If you are unsure how much 3G data costs, or what your data allowance is, then contact your mobile network operator.
BBC iPlayer uses HLS (HTTP Live Streaming) video which uses adaptive bitrate technologies. This enables us to detect the strength of your 3G connection and serve the appropriate video quality.
If you have low 3G signal strength then the video stream will adapt down to suit your 3G connection speed. If you move onto a stronger signal then the video stream will automatically improve in quality. The idea is to give you the best possible experience wherever you are.
Mobile network operators calculate data usage by the megabyte (MB) and you may have a monthly 3G data usage allowance.
To help you calculate how much data you might be using when watching or listening to BBC programmes over 3G networks we have provided file size estimates as a guide,
Watching 30 minutes of video may consume between 25MB and 112MB of data depending on your available connection speed.
Watching 60 minutes of video may consume between 50MB and 225MB of data depending on your available connection speed.
Listening to 30 minutes of radio may consume up to 30MB of data.
Listening to 60 minutes of Radio may consume up to 60MB of data.
Many mobile phones include a mobile network data usage tracker which will show you how much mobile data you have used.
You can find the mobile network data usage tracker on an iPhone running iOS 5 or above by going to Settings > General > Usage > scroll down to Cellular Usage.
If you are unsure how much 3G data costs, or what your data allowance is then contact your mobile network operator.