Facebook Live allows you to stream 90-minute clips of whatever you’re doing, and since its launch, we’ve been gifted real-time broadcasts of everything from a woman giving birth to an octopus kite swaying dreamily in the sky. Now, TechCrunch reports that the service will soon let you broadcast for as long as you want, ensuring at least a handful of new 24-hour eagle nest feeds.
Though the feature is meant to be used by groups with enough bandwidth to stream for impressive periods of time, it also relies upon users to actually watch those streams. Which leads us to a pressing question: What might happen to your data plan if you stumble upon a livestream of a pen full of puppies and — I don’t know — watch it for six hours sans Wi-Fi?
First of all, your phone will probably die. Second of all, you can probably expect a very upsetting phone bill. Despite the titillating content possibilities that come with unlimited livestreams, viewers will still have to sacrifice a significant amount of data to watch them.
The data your phone gobbles up is determined by a few things, but usually comes down to the quality of video. Most companies that provide livestreams automatically adjust the quality (which usually ranges from 240p to 1080p) based on whether you’re on a desktop using Wi-Fi or on a phone using data. If you’re doing the latter, that probably means your phone is being dealt a smaller file to stream, for the sake of its processing ability and your data plan.
But many livestreaming services don’t actually want to reveal those details. Periscope, for instance, doesn’t share specs on its data usage stats aside from declaring its “bandwidth usage is comparable to other streaming video applications.” (Not helpful.) And unsurprisingly, Facebook wouldn’t offer any details on the bit rate of its Facebook Live videos when I reached out.
But we can do a rough estimate anyway, using what we know about the data it takes to stream YouTube videos online, thanks to many data-obsessed people and some basic math. (Tip: Every time I mention a number, just imagine your favorite Beyoncé music video and it’ll make this math seem easier.) A 240p video, for instance, uses about 1.66 megabytes of data per minute. A 360p video uses 2.66 megabytes per minute, and a 480p one (typically YouTube’s default setting) uses 4 megabytes per minute.
A quick measurement for a Facebook Live video on my desktop shows that it downloaded at about 3.8 megabytes per minute. This means that when you’re streaming Facebook Live on your desktop with a healthy Wi-Fi connection, the video quality is close to 480p. It would make sense, then, that Facebook’s mobile streaming quality would be a notch lower than that, anywhere between 240p and 360p.
So if you happened to watch a livestream for 24 hours on one of those low-quality video streams, you’d be using about 2,390 megabytes or about 2.4 gigabytes. That’s a little more than half of my monthly data plan. And even if you split that viewing into just one hour a day per month, you’d still be screwed on your phone bill. And that doesn’t even take into account the fact that the Facebook app is already a notorious data hog, in part because it automatically plays videos as you scroll through your feed.

Just think of that next time you spend an hour watching Esther the Wonder Pig bathe.