Comcast Xfinity Data Caps: How They’ll Affect Your Online Experience

Xfinity has a 1.2 terabyte (TB) monthly data cap on some internet packages. They’ll exempt you from fees for the first month. Afterward, you’ll need to pay $10 per 50 GB of data they add to your account. With 1.2 TB of data, you could stream up to 205 hours of 4K video.
Comcast Xfinity modem and router

As a former Xfinity subscriber, I want to share some of my experience. That way, you’ll know what you’re getting yourself into and how to adapt.

In this guide, I’ll cover their data cap, how it’ll impact your online experience, and what you can do with your limited speeds.

Read on to learn more about Comcast’s data caps.

What Is Comcast Xfinity’s Data Cap?

Xfinity enforces what they call a ‘data cap’ or ‘data usage plan.’ These limits put a cap on the amount of data you can use per month without paying fees. Comcast has a 1.2 terabyte (TB) data cap.

When passing this data cap for the first time, Xfinity won’t charge you. But they will if you pass the limit twice or more. They’ll add blocks of data to your account.

Each block has 50 gigabytes (GB). They’ll charge you $10 per block they add to your account. With 50 GB, you could play 1,650 hours of online games and stream 13 hours of 1080p videos.

These extra charges can go up to $100. However, they don’t limit how many blocks they give you. That means you could use a yottabyte (which is A LOT) of data and still pay $100.

Xfinity enforces the data cap in every territory they support.

Back in 2012, Comcast had a 250 GB cap. In 2016, they had a 1 TB limit. And in 2021, they raised it to 1.2 TB.

As more people take to the web for work and entertainment, they’ll likely increase their data cap. And maybe even remove it. Though, I’m not holding my breath.

Data Cap for Internet Essentials

Internet Essential subscribers still face the same 1.2 TB data cap as other plans. With one difference.

Instead of paying up to $100 for data overage fees, you’ll only pay a max of $30.

Data Cap for Prepaid Internet

Xfinity Prepaid internet has a 1.0 terabyte (TB) data cap. Once you pass this cap, you’ll need to pay a $10 overage fee per 50 GB you use.

I couldn’t find any information on whether there’s a max overage charge threshold for this plan.

If you stream a lot of 4K content, I recommend avoiding Xfinity Prepaid.

Why Does Xfinity’s Data Cap Exist?

Because it makes them more money. I’d like to play the devil’s advocate and try to see things from Comcast’s side. But a leaked memo ALLEGEDLY says their data caps have nothing to do with network congestion [1, 2].

With an increase of people working from home, streaming 4K video, and online gaming, why not? There’s not much competition regarding internet service providers. So there’s almost nothing that can stop them from enforcing such rules.

Also, they’re making up to an additional $100 per month from those who pass the data cap. Or they’re tacking an extra $30–35 per month for customers to upgrade to their Unlimited Internet plan.

How Do Data Caps Impact Online Experiences?

A study said that data caps do a great job of getting people to use less data [3]. But for the most part, it seems like a scare tactic. In the next section, I’ll point out that it’s HARD to pass the data cap.

However, many will still fork over the extra money for an unlimited data plan before paying attention to the amount of data they use [4].

The most significant issues with data caps involve 4K streaming and gaming. Let’s use Google Stadia as an example. If you used that as your primary gaming console for a month, you’d use an estimated 1,386 gigabytes (GB) of data [5].

What Can I Do With 1.2 Terabytes of Data per Month?

I found a calculator on AT&T’s website and I have to admit. I had some fun [6] Here’s a bunch of things you can do online with 1.2 terabytes (TB) of data:

Online gaming1650+
4K video streaming204
Music streaming8500
*Surfing the web2,000+
1080p video streaming350
**4G Voice Over Internet Protocol (VoIP)60+
This table shows what you can do with 1.2 TB of data.

*They say you’d only use 15MB per hour. What people do on the internet varies. So take this number with a grain of salt.

**This came from Verizon’s data calculator [7].

These numbers only reflect the number of hours you have per task.

For example:

You’d have to ONLY use your internet for streaming 4K videos to reach the 204-hour mark.

In addition to this table, with only 6.40 gigabytes (GB), you can send over 40,000 emails. 75% of these hypothetical emails don’t have attachments. 25% do.

By the looks of this table, a single person will have difficulty reaching the 1.2 TB data cap. Even if you had a bot play World of Warcraft 24 hours a day, you’d only reach around 720 hours a month.

Watch out for 4K streaming, though. That’s the biggest data hog. Especially if multiple people in your home stream 4K videos.

In that scenario, you’d reach the data cap fast. And you’d want to consider Xfinity’s Unlimited Internet plan.

Here’s How To Avoid Xfinity Data Cap Charges

If you use your own router, you can pay an extra $30 per month to upgrade to Unlimited Internet. Whereas, if you get the xFi Complete Kit (modem/router combo), you can get unlimited data for $25 per month.

Why would you pay the extra $30 when you could just pay $25? Because you’re stuck using a gateway. It’s cheaper to replace separate devices. You also have less to deal with if you ever cancel Xfinity.

Then there’s Gigabit Plus. Three thousand sweet megabits per second (download AND upload) but with a catch. It’s $300 per month. But at least you won’t have a data cap on those fast speeds.


Avoid streaming 4K videos or gaming in 4K. Those use the most data.

Otherwise, just monitor your data usage. Despite Xfinity’s business practices by implementing the data cap, they DO offer a way to track your data. You have a couple of ways to do this.

Log into your Xfinity account in your browser.

You can also log into your Xfinity mobile app. Log into your account, tap ‘Internet’ on the top left bar, and scroll down. Toward the bottom of your screen, you’ll see your data usage.

You won’t see these usage meters if you’re not the account manager or primary user.

Now that you can visualize your data. Compare that to the online tasks you and your family do. Is there any way that you can reduce your bandwidth?

If you use a virtual private network (VPN), consider disabling it when not necessary. These increase your data usage by 5–15% [8].

When binging YouTube, Netflix, or other streaming sites, consider turning down your video quality. 720p videos aren’t that bad. And if you only listen to YouTube as background noise, use the browser extension YouTube Audio (Firefox extension).

It disables video. I use it when listening to ASMR—I mean documentaries.

Torrenting. When torrenting a file, you’re simultaneously uploading AND downloading files. That means a torrent may use double the file size you’re downloading.

Then there’s wasted data. Data you receive from peers that’s not required. And while seeding helps other people out, it uses a lot of data.

You’ll want to consider pausing or stopping seeds.

How Does Xfinity’s Data Cap Compare to the Competition?

Considering a different internet service provider? Think again. Here’s how Xfinity compares to competitors:

Internet Service ProviderData CapOverage Fees
Xfinity1.2 TB$10 per 50 GB block
AT&T1.0 TB$10 per 50 GB
WOW!1–3 TB (depends on plan)$10 per 50 GB
Cox1.25$10 per 50 GB
Mediacom400 GB–6 TB$10 per 50 GB
Google FiberNoneNA
This table compares data caps among different internet service providers. It also shows how much ISP charges per certain amount of data they add.

I threw Google Fiber in there for fun. WOW! has a 3 TB data cap on their 1,000 Mbps plan, which triumphs over Xfinity. A company that maintains its 1.2 TB data cap on a 1,200 Mbps plan.

As we can see, Xfinity didn’t fare well against the competition. Except for AT&T and the lowest plan WOW! offers.

FAQ: Comcast Xfinity Data Caps

Don’t leave yet. I’m not done. Check out frequently asked questions about Xfinity data limits.

Will VPNs Help Me Get Around Throttling?

A virtual private network (VPN) won’t help you get around data limits. A VPN will hide traffic from your internet service provider (ISP). But it won’t hide the amount of data you use.

Despite my claim, I invite you to use a VPN and see whether it impacts your data usage.

Should I Use Xfinity’s Unlimited Data Plan?

Subscribe to Xfinity’s Unlimited Data plan if you use over 1.2 terabytes (TB) of data monthly. Before subscribing, you’ll need to make sure Xfinity offers the plan where you live.

What Happens When You Use All of Your Xfinity Data?

After you use 1.2 terabytes (TB) of data per month, Xfinity will add blocks of data to your account. Each block consists of 50 Gigabytes (GB) of data. And each block costs $10.

Xfinity won’t charge you during the first month you exceed their data cap [9]. No matter how much data you use. You’ll pay a max of $100 for data overage charges.

Wrapping Up

Xfinity has a 1.2 terabyte (TB) data cap for almost all their plans (except Xfinity Prepaid). Xfinity Prepaid has a 1.0 TB cap. You’ll need to pay an extra $10 per 50 GB of data you’ll use.

The internet service provider doesn’t have the best reason to implement this data cap. They also don’t offer the most gracious data cap compared to competitors.

But you’ll likely never reach the data cap. And if you do, you can either change your plan or reduce your internet usage.

Also, keep in mind that slow internet speeds don’t come from data caps. If that’s an issue you’re facing, check out a guide we wrote on fixing slow Xfinity internet.

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