How much data does FaceTime video calling use on the iPhone?

How much data does FaceTime video calling use on the iPhone?

When using FaceTime on a Wi-Fi connection your data plan is not used. Similarly, no cellular calling minutes are used during the video portion of a FaceTime call.

FaceTime calling can be used over a cellular data connection with an iPhone. Using FaceTime over a cellular data connection (3G / LTE) will use your data plan.

Five minutes of FaceTime video calling uses up to 15 MB of data.

Comments

In your answers regarding the data used for five minutes of FaceTime audio and five minutes of FaceTime video you used two different units. For audio you state 5mb and video 15MB. MB megabytes is a unit of size while mb megabits is a unit of speed per second download. In addition one mb is 1/8 the size of one MB. The usual ratio between the two is 8:1 (mb/s to MB of data). Which one is it? Have others asked about this? Looking forward to your response as it will help me determine my usage vs data limits.

I'd like a response too so I can decide whether it's worth it or just wait til my wifi is fixed