With the popularity of online streaming from Apple, Netflix, Hulu and other services, more and more people are getting their TV entertainment from the Internet. On the other hand, unlimited services, born in the 1990s, no longer seem sensible to the ISPs, and they have either already instituted data caps — or plan to do so in 2012.

As a result, one of the new blights of our Internet life is the process of keeping track of our monthly data usage. Here’s how to do it with Comcast. (Note, Comcast has a complex site and there are lots of different ways to do things. I’ve picked a simple approach for beginners.)

1. First, if you’re a Comcast customer but don’t already have an online management account, you’ll need to do that first. Otherwise proceed to step #2. Perhaps the easiest, but not only, way to create an online access account is to go directly to Comcast.com.

http://www.comcast.com/default.cspx

On the right side, in blue, click on “Manage Your Account.”

On the left side of the next page is a sign up link. Have your latest bill handy. When that’s done, you’ll have a userid and password.

2. To check your data usage, here’s a very direct and simple link to Comcast’s Customer Central. Click on “Sign in.”

https://customer.comcast.com/Public/Home.aspx

Customer Central Login

That takes you another short login page. After you sign in, you’ll see a page titled: “My Account Summary.”

“My Account Summary”

Look for the tab at the top: “Users and Settings”. Click it.

3. Then you’ll see a page that allows you to manage your Account. On the upper right is a progress bar that shows your usage for the month so far.

“Manage My User Accounts”

If you want to get even more detail, click on the link under the progress bar named “View details.” At this point you’ll see a bar chart showing the last three month’s usage.

When you’re done, at the far upper right of the page, next to the date-time stamp, is the Sign Out link.

Comcast says that 99 percent of their customers use significantly less than the 250 GB limit. But if you’ve been doing a lot of TV streaming, you may want to start monitoring to see how you’re doing. Even though I live on the Internet, and my wife does a lot of Netflix viewing on her iPad, we’re not anywhere near the limit. YMMV.