How much data (in megabytes) does Skype consume in a 1 minute audio call? And how much data does Skype consume in a 1 minute video call? Is it fixed or does it vary with the mobile version or PC version of Skype?
As Gaurav Joseph has said you can monitor this through the resource monitor or using another network monitoring tool to obtain your usage.
As an approximate guide Skype says the following are examples of typical data usage.
- Skype-to-Skype calls: 50kbps or around 375KB for one minute of calling
- Calls to mobile numbers or landlines: 6-20 kbps or around 150KB for one minute of calling
- Video calls between two mobile phone devices: 500kbps
- Video calls between a mobile phone and a computer: 600kbps
If you take these figures you are looking at approximately 3.75 MB for a video call between two mobile devices for 1 minute.
Skype also recommends different bandwidth requirements for different situations.
HD video calling has a recommended upload and download speed of 1.5Mbps both ways so you are looking at about 22.5 MB per minute.
To answer your last question as Skype is a peer to peer application and will try to make the best use of the bandwidth it has available so the rate is variable and not fixed.