What Does Cat Mean for Ethernet Cables? An Explanation

What Does Cat Mean title page

When it comes to ethernet cables, you’ll find that there are many different words used to describe them.

If you jump on Amazon to buy an ethernet cable (like this one), you’ll likely see terms that describe the:

  • Length of the cable (in feet)
  • Bandwidth of the cable (in MHz)
  • Type of connectors on the cable (e.g. RJ45)
  • Configuration of the wires in the cable (unshielded twisted pair or shielded twisted pair)
  • Size of the wires in the cable (e.g. AWG standard)

Not only is this confusing, but it can be overwhelming as well.

The good news is many of these specifications used to describe ethernet cables aren’t very important. They’re standard values that don’t really tell you how the cable will perform.

In addition to the list above, there’s one final term that’s used to describe ethernet cables. This is one you don’t want to ignore.

That term is “cat”.

What does cat mean? Are we talking about animals here?

When it comes to ethernet cables, the term “cat” is short for category. The category of an ethernet cable tells you the standard it was made to, which includes the speed (i.e. bandwidth) that the cable supports. This is one of the most important factors when choosing an ethernet cable.

In this post, I’ll break down why the category of an ethernet cable is important to pay attention to, as well as the most common categories of ethernet cables you’ll come across.

What Does Cat Stand For on an Ethernet Cable?

As I mentioned above, cat is short for category.

When it comes to ethernet cables, you’ll see “cat” all over the place. Not only will you see it in the product description when you’re buying them, but you’ll also see it on the side of the cables themselves.

Does this look familiar?

Cat label on ethernet cable

The category of an ethernet cable is probably the most common way to describe them. That’s because the category of a cable will give you the most important information about it.

Solid cliff hanger there. Let’s cut to the chase.

Why Is the Category of a Cable Important?

If you know the given category of an ethernet cable, you most likely don’t need to know anything else about it. The category of a cable essentially provides a summary of the cable’s performance.

This is why the cat of a cable is so important.

What about a cable’s performance do people care about?

A cable’s performance basically boils down to the one question that people are concerned with: what’s the maximum speed (i.e. bandwidth) the cable can support?

The category of a cable represents a certain manufacturing standard that it’s made to. If you took 100 cables of the same category, they’ll all have the same performance characteristics.

This is how you’ll know the speed a cable supports if you know what category it is. As you’ll find out later, different categories of cables will have different performance specifications.

So why do you need to know the maximum speed a cable supports?

The speed a cable supports can play an important role in your home network. If you’re using ethernet cables that can’t support the speed of your internet plan and devices, your cables can slow down the speed of your entire network.

Check out this other article I’ve written if you want more context on how ethernet cables can slow your network speed.

If you know the cat of a cable (and therefore the speed it supports), you can make sure you’re using cables that won’t slow down your network.

How Many Ethernet Cable Categories Are There?

Ok we’ve established that the category of a cable is important to the performance of our networks. Now let’s talk about the different categories of ethernet cables.

One thing that’s important to understand up front is the fact that ethernet cables have evolved over time. The same can be said for your internet connections.

Who can forget connecting to the internet with a dial-up modem in the early days of the internet?

Enough of that. Let’s stay on topic here.

The bottom line is that internet connections have gotten faster over time. Ethernet cables have followed suit by supporting faster data transfer speeds with each new category that’s developed.

When it comes to ethernet cables, they’re more or less labeled in the order they were developed. The first ethernet cable category to be developed was cat 1.

Extra credit for originality there.

Following cat 1 was cat 2. Cat 2 was followed by cat 3, cat 4, and so on. This naming convention more-or-less followed the same pattern all the way up to the latest cable category, which is cat 8.2.

It’s important to note that some categories have multiple versions (e.g. cat 8.1 and cat 8.2). In other words, there are more than 8 categories of ethernet cables.

In fact, 12 ethernet cable categories exist today.

Although this may seem overwhelming, as we dive more into each category you’ll find that ethernet cables may not be as complicated as they seem.

What Are the Ethernet Cable Categories?

It’s helpful to take a minute to look at the big picture here.

To make things easy for you, here’s a list of all the ethernet cable categories and the year each category was developed:

Ethernet cable category overview

As you can see, over time it looks like new ethernet cable categories have been developed every 3-5 years.

The key takeaway here is that although there are many different categories of cables, only a few will be applicable for your needs. For example, do you really think people are still using cat 1 ethernet cables that were developed in 1983?

I don’t think so.

Later in this post, I’ll talk about the cables that are most applicable to you today. Spoiler alert: there are only a couple categories you need to be familiar with.

In the meantime, let’s dive into what we really care about: the speeds that each of these categories supports.

What Is the Maximum Speed of the Ethernet Cable Categories?

Each time a new category of ethernet cable is developed, the new category is an improvement of the previous version.

Think about it like your iPhone.

Each time a new iPhone version is released, it has feature improvements that make it “better” than the previous version.

Ethernet cables are pretty similar. When a new category of cable is released, the new category usually supports a faster maximum speed than the previous version. In some cases, the category will support the same maximum data transfer speed, but over longer lengths of ethernet cable.

Here’s a good breakdown of the maximum speed that each ethernet cable can support.

Ethernet cable category comparison

It’s crazy to see how far ethernet cables have come over the years. They used to support 10 megabits per second (Mbps), which you wouldn’t even be able to use today with current internet speeds.

On the other hand, some of the newer categories (e.g. cat 7 and higher) of cable support speeds much faster than the everyday user would ever need. These cables are mostly used in datacenters where extremely high performance is needed.

One thing to note is that regardless of the category, ethernet cables won’t work properly if they’re over 328 feet long. Chances are you’ll never need a cable that long, but you should be aware of this nonetheless.

What Are the Most Common Ethernet Cable Categories?

I’ll start by saying this again: don’t be overwhelmed by the fact that there are currently 12 categories of ethernet cables.

As you can see from the diagram in the previous section, many of the categories support data transfer speeds that don’t apply to you. I’m talking about the categories on both sides of the spectrum here.

Some older cable categories support speeds that’re much slower than you’ll need for your network, while some of the newer categories are overkill.

In fact, we can ignore the majority of the cable categories because of the speeds they support. This is where it gets much easier.

For most home and office networks, the most commonly used cable categories are cat 5e and cat 6.

For your reference, I’ve written an article about the difference between cat 5e and cat 6 cables if you’re curious about this.

See? Ethernet cables aren’t as complicated as they seem.

Out of 12 categories of ethernet cables, only 2 are applicable to the “normal” home and office network.

Cat 5e and Cat 6 Cables

Cat 5e cables support data transfer speeds up to 1 gigabit per second (Gbps). 1 Gbps is generally sufficient for most networks.

With that said, we’re fast approaching the days where internet plans can provide speeds of 1 Gbps or faster. As a result, some networks will need ethernet cables that can support speeds faster than 1 Gbps.

That’s where cat 6 cables come in.

Cat 6 cables are interesting in that they support speeds up to 10 Gbps, but only for ethernet cables shorter than 180 feet. For cable lengths between 180 and 328 feet, they support speeds up to 1 Gbps (just like cat 5e cables).

Despite the unique characteristics of cat 6 cables, most people don’t need cables longer than 180 feet. To put it simply, cat 6 cables should be the next category of cable you get if cat 5e cables won’t suffice in your network.

So which of these cable categories should you be using?

If you aren’t sure what type of ethernet cable categories you have in your home network, check out this other article I’ve written. It’ll help you get this sorted out.

If you currently have cat 5e cables in your environment, you should be fine. You’ll only want to upgrade to cat 6 if your internet plan provides speeds faster than 1 Gbps.

If you’re looking to buy new cables, I suggest you buy cat 6 cables so you don’t have to worry about replacing your cat 5e cables in the future. If you get cat 6 cables now, they’ll be able to support your network for a long time without the risk of slowing it down.

Wrap Up

You’re now equipped with everything you need to know about ethernet cable categories. You can confidently make decisions about what cables you need without getting overwhelmed by a term that you don’t know.

Remember, if you focus on getting cables that are the right category for your network, you shouldn’t really have to worry about anything else (aside from the length of the cable).

If you have any questions about this material, please drop a line below in the comments section.

If you found this information helpful, here are some other posts that you might find useful as well:

How to Tell What Type of Ethernet Cable You Have

The Difference Between Cat5e and Cat6 Cables

How to Extend an Ethernet Cable

Does Ethernet Cable Length Affect Network Speed?

Can an Ethernet Cable Slow Your Internet Speed?

Ross Ricky

Ross Ricky is an engineer and cybersecurity professional who wants nothing more than for you to get the most out of your home network.

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