Here's How Much Data A FaceTime Call Uses Per Hour - SlashGear
As seamless as Apple makes it look, FaceTime isn't magic. Like every other video-conferencing app, it works by streaming video and audio between devices, which means the moment you're off Wi-Fi, it's burning through your mobile data. But how much data are we actually talking? Unlike minutes or texts, you don't get a carrier ping telling you what a FaceTime call just cost. But you can find out.
