How Easy Is It to Burn Through a 1TB Data Cap?

We've already written about Comcast's push to saddle more of its customers with a broadband data caps—limits on the amount of data they can use each month without incurring additional charges. Possibly to make the caps more palatable, the company recently upped its data cap from 300 gigabytes (GB) to 1 terabyte (TB).

That sounded like a lot of data, so we investigated how easy it would be to burn through a terabyte of data, and whether you'd be better off paying the extra $35 a month to get the unlimited data plan the company is offering.

The truth is, while we're still not fans of data caps, we don't think that many families will have to worry about hitting a 1TB data cap any time soon. (See the math below.) But as more entertainment moves from traditional cable lines to the internet and 4K video becomes more commonplace, these data caps could eventually affect more of us.

"The prospect of a U.S. household reaching 1TB of monthly use is still several years away," says Michael Greeson, co-founder and director of research at the Diffusion Group (TDG), a research and advisory group. "Even heavy Netflix households are lucky to hit 250GB to 300GB a month, so there is still a lot of headroom."

Dan Rayburn, principal analyst at research firm Frost & Sullivan, agrees. "The reality is that very few households will ever hit a 1TB data cap, despite many saying that they don't like living with" such caps, he says.

Here's How You Get to 1TB

Okay, so you're not likely to hit 1 TB of data in a month, but that doesn't mean it's impossible. We asked Rayburn, who also runs the streamingmedia.com website, for a few scenarios in which a household would reach that level of data usage.

We used video streaming for our calculations because it uses so much data—simpler tasks such as browsing web pages or posting Instagram photos don't even come close.

According to Rayburn, the average Netflix video is 90 minutes long and eats up 1.6GB of data per hour (that's 2.4GB per 90-minute video). Netflix itself cites different numbers, estimating that standard-definition streams consume about 1GB per hour while high-def videos chew up 3GB per hour.

We think Rayburn's number is more realistic, because even if you're ostensibly streaming HD video, the quality gets adjusted dynamically based on the available bandwidth at your home.

We could do the calculation using any of these figures, and the results would be similar.

Using Rayburn's number, in a single month you'd have to stream 416 Netflix videos of 90 minutes each to hit a 1TB data cap. Got four people in your family? You'd each need to watch 104 videos per month, or more than five hours of Netflix every day. That's well above one analyst's estimate of typical usage, which has Netflix subscribers spending two hours each day using the service.