How much data (MB) does Skype consume in a 1 minute call?
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
How much data will Skype use on my mobile phone?
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.
How much bandwidth does Skype need?
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.
You can also use sysinternals process explorer to monitor skype.exe. In "disk and network" tab it shows you exact speed and number of bytes transfered over network.