Skype Bandwidth Usage
Solution 1:
From what I've read on Skype faq recommended speed for calling is 100kbps, from that we can calculate bandwidth usage per hour.
100kbps*60*60 = 360000 kb(kilobits)/h = 43.9453125 MB(megabytes)/h
44MB*8h(max)*3days = 1056MB ~ 1GB
Video calling/Screen sharing requires 3x bigger bandwidth but that's not even close to 16GB!
But if you were browsing the internet and watching videos while chatting 16GB seems reasonable.
Solution 2:
Use Skype's detailed call information to see the average bandwidth used. For voice calls, it is usually pretty low, around 2-8kbps, video calls will of course use more bandwidth.
If you want to know how much bandwidth Skype uses per hour in your specific case, just use any internet traffic monitor apps to see how much bandwidth Skype uses and talk for a few hours to get more precise data.
Or just use Windows' standard Resource Monitor utility. Press Start button, type resmon
and hit Enter. Select the Network tab and you will see how much bandwidth Skype is currently using:
As you can see, my voice calls use a total of ~9700 bytes per second (~3500 B/s upload, ~6200 B/s download).