If you’re being careful about how much data you use in your internet or cellular plan, then you’re probably aware that audio and video are the sources of most data usage. When you combine the two into something like YouTube videos, then you’re really going through data fast. How fast exactly?
It will depend on what video resolution you choose. The standard video resolution is standard definition, 720p. This resolution uses a GB about every 40 minutes, which means that 7 hours of straight watching (no breaks or time between videos) will use up 10.5 GB of data. Assuming you’re not going to be playing a video literally every second of those 7 hours, your data usage will be a little less than that.
If you want higher definition videos, like 1080p, you’ll use up 21 GB in 7 hours. 4K Ultra HD videos are rare on YouTube, but if you really want to watch your data burn, that’s the way to go. 7 hours of watching 4K UHD will use up over 100 GB.
If you want to conserve data on the other hand, consider lowering the resolution a little. Especially if you’re using a smartphone or other small screen, it’s often hard to even tell the difference. If you lower the resolution to 480p, 7 hours of watching YouTube will use up only 3.5 GB, and at 144p, you’ll use less than a single GB.