Maximum Ethernet Cable Length

Written by Don Schultz, trueCABLE Senior Technical Advisor, Fluke Networks Copper/Fiber CCTT, BICSI INSTC, INSTF Certified

So, you bought that 1,000 foot box of Cat6 Ethernet cable and intend to run the entire box from your house to your barn or guest house. “This will be great!” you are thinking. “I can finally shuttle off that annoying relative to another part of my property and they can surf the Internet all day….without bothering me!” you tell yourself.

Don’t pack up your relatives yet. You have some calculating and installation to do! How far can you run an Ethernet cable? Is there a minimum Ethernet cable length? Often the technicians at trueCABLE are asked what are the Cat5e vs Cat6 distance limits. Would it surprise you to find out that Category is not the primary factor in Cat5e range or any particular Category for that matter? There are some notable exceptions based upon application speeds that may affect your Cat6, Cat7, or Cat8 distances and we will cover them. Suffice it to say that the main limiting factor is what copper is physically capable of handling from an electrical standpoint. This means criteria like ambient temperature come into play--when temperatures go up Cat5e length (actually ANY Category cable length) permitted gets shorter.

Get ready to throw that 328 foot (100m) value out the nearest window, or at the very least understand that often quoted 328 foot distance number is saddled with a lot of hidden gotchas and caveats. Life is never simple, is it?

Ethernet cable distance chart (simplified)

Huh. Seems like we have a common denominator—328 feet is the maximum “channel” length of an Ethernet cable run no matter what. So don’t get any ideas; Cat6A will have the same maximum length of ethernet cable as Cat6. Essentially, 328 feet is merely our starting point. You get to go shorter from there.

There is no established minimum Ethernet cable distance in the ANSI/TIA 568 standard.

Before we go too far down the technical rabbit hole, we need to define what a channel is. An Ethernet channel is the complete end-to-end communications route from a router/switch to something you use like a computer. Of course, there are variations on this theme, but suffice it to say that from powered-device to powered-device the maximum ethernet distance possible is 328 feet under ideal conditions when you are not seeking to push the edge case speed limit for Cat6, for example.

There are ways to get devices connected that are much farther away, but they don’t make use of the same segment of cable; there is more than one. This idea makes use of powered Ethernet switches that “renew” your signal. We won’t be talking about that particular method for this blog, so assume no “booster” equipment is helping extend your communications channels.

Single Patch Cord Used for Entire Connection (Channel)

Here is an example of a super simple channel, plugging in a typical home WiFi combo router and switch to a gaming console:

Simple patch cord used for entire connection

In the above example, a cable with RJ45 connectors (also called plugs or ends) is attached to both ends of the cable. This example is two things:

• An Ethernet patch cable. By definition, an Ethernet cable that has RJ45 plugs on both ends is a patch cable.
• Since there is no other hardware or cabling in the mix, this Ethernet patch cable is functioning as the entire communications channel.

For the typical DIYer, this is how most installations will look. A large number of people assume that an Ethernet cable has RJ45 plugs on both ends and this is how Ethernet cables are supposed to be connected to your stuff. Why? Well, most folks have not seen anything different or didn’t understand what they were looking at even if they had.

Are there limitations to how long a patch cable can be that separates them from the solid copper stuff? Oh yes, because patch cords are constructed from stranded copper conductors that automatically have additional signal degradation above and beyond that seen with solid copper conductors. Complicating things even more, conductor gauge is another factor to take into account as in recent years most patch cords are using 26AWG and 28AWG stranded copper conductors. This maximum length will be anywhere from 50 feet (28AWG) to 279 feet (24AWG) with 26AWG being right in the middle at 223 feet.

It is not recommended to construct an entire cabling system out of patch cords, especially if your intention is to run cable drops from room to room or outdoors. 8P8C (aka RJ45) connectors are fragile and most patch cords cannot cope with outdoor conditions.

If your connection:

• Exceeds 50 feet or requires multiple patch cords connected together to get from A to B
• Goes from inside to outside
• Runs from one part of your structure to another, especially through walls/floors

…then you should utilize solid copper Ethernet cable. This changes the rules and gives a great deal of flexibility.

Permanent Links and Structured Cabling Systems

When we refer to a “permanent link” this means a permanently installed Ethernet cable, typically found inside walls. Such permanent connections are constructed using solid copper Ethernet cable, and terminated from keystone wall jack > keystone wall jack or patch panel > keystone wall jack.

Here is a simple example of a permanent link and the beginning of a “structured cabling system”:

Simple permanent link constructed using solid copper Ethernet cable

Permanent links are typically used in:

• Commercial installations
• New construction residential installations
• Retrofit installations done by savvy DIYers desiring flexibility and clean looking installs (like you!)

Permanent links use 22, 23, or 24AWG solid copper Ethernet cable per the ANSI/TIA 568 standard. Permanent links may be up to 295 feet long at 68℉ and start off as raw unterminated cable that must be cut to length and terminated by an installer.

Wait! Where did the 328 foot number go? The solid copper portion of your installation, when combined with two patch cords at both ends, adds up to the maximum permitted 328 feet. Notice that this depends on ambient temperature and patch cord copper gauge to even reach the ideal maximum of 328 feet. So much for 328 feet, right? Please see Calculating Ethernet Cable Overall Channel Length for Success for charts to figure this all out.

Of course a female to female connection is absolutely useless as the connection is not complete yet.

Combining Permanent Links with Patch Cords

A permanent link becomes part of a channel when you plug in Ethernet patch cables to complete your connections at both ends.

Here is an example of a channel that contains a permanent link and patch cords:

Simple Overall Channel With Permanent Link and Patch Cords

Wow! Ok, things just got more complicated. Take your imagination with me on this one. In this example above, there is a permanent link installed from your living room to your far bedroom where your WiFi is always horrible. You know that room I am talking about! At both ends of the permanent link are female keystone jacks. That link is “permanent” because you have no intention of ever moving it again.

From each keystone jack is an Ethernet patch cable connecting up a device that gets power. At one end, your patch cable is plugged into the WiFi router you got last holiday season. At the other end in the far bedroom, you have a second patch cable connecting the other keystone jack to a gaming console.

Did the rules around maximum ethernet cable length change? Nope. From end to end, including the patch cables, how long can ethernet cable be? You are still limited to 328 feet in the best case scenario. Remember, not only are we dealing with factors like temperature but also patch cord gauge. This means you can have variations like this:

Chart assumes 68℉ with 295 foot solid copper permanent link

Frequently Asked Questions

Will shielded Ethernet cable help get more distance?

Yes and no. Shielded Ethernet cable is better at dissipating ambient heat, so shielded permanent links can be longer at a given temperature but the 328 foot hard limit is still present. That said, shielding makes no difference to patch cord conductor gauge or if you need to go shorter due to higher speeds (like 10G on Cat6 for example).

What happens if I decide to run Ethernet past 328 feet? Will the cable simply cease to work?

It would be nice if things were that cut and dry. If you decide to exceed the maximum Ethernet lengths given here your results will vary based upon your application speeds, ambient temperatures, etc. You may only see a few dropped packets here and there or you might only achieve 1Gbps when you were expecting 5Gbps. This is where cable quality, termination quality, and EMI/RFI can start to play outsized roles. You can be certain that no matter the scenario, reliability of your cable run is at risk!

Why is solid copper Ethernet cable vs stranded copper Ethernet cable capable of going farther?

This is known as the “skin effect”. Stranded copper conductors are constructed using very fine copper wires with the thickness of human hair. To an electron riding down a conductor wire, the spaces between each human sized hair strand may as well be the Grand Canyon. Quite simply, solid copper has more surface area for the electrons to ride on. See Solid vs. Stranded Ethernet Cable for more information.

I need to go 500 feet, but Ethernet cable cannot run that far. Is there an alternative?

Absolutely and it does not have to be complicated to overcome this (in fact, it is in many cases more straightforward and around the same price with far less effort). Fiber optic cable is the ideal long haul cable, designed for high speeds and long distances (or really high speeds over shorter distances) far exceeding that of copper Ethernet. See Cat7 vs Cat8 vs Fiber Optic Cable: Ultimate Guide [2024] for an easy read with a video on the subject!

Summing Up

Based upon the limits and other rules, you can see a huge number of ways to run Ethernet in your home or business despite the maximum ethernet cable length. Which path you take is often dedicated by budget, skill level, environment, and more.

So, there it is. A potentially confusing topic made easier to understand!

HAPPY NETWORKING!

trueCABLE presents the information on our website, including the “Cable Academy” blog and live chat support, as a service to our customers and other visitors to our website subject to our website terms and conditions. While the information on this website is about data networking and electrical issues, it is not professional advice and any reliance on such material is at your own risk.