The amount of mobile data used by Netflix depends on the quality in which you’re streaming. If you have Netflix Basic, you’ll use much less data streaming in HD than if you have Netflix Premium and stream in Ultra HD. Traditionally, a good rule of thumb is that the higher the quality streamed, the more data it’ll need to consume. According to Netflix, Ultra HD streaming can use as much as 7 GB of data per hour. (Compare this to just 1 GB an hour for SD streaming content.)