Are Longer Ethernet Cables Slower?

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The distance that an Ethernet cable must cover can be quite large, even in a home network environment, so should you worry about the length of cable you are using, and does a longer cable really slow you down?

Longer Ethernet cables can be slower as latency increases the further the signal has to travel. However, Ethernet signals travel at around two thirds the speed of light, so you likely won’t notice any difference when comparing shorter lengths of cable. 

The short answer is that the length of Ethernet cable doesn’t really matter when it comes to the lengths we will be using in our home networks, but there is a limit to the length of a single cable before you start running into some issues.

How Long Can an Ethernet Cable Be?

There isn’t a defined limit to the length that a single run of Ethernet cable can be, however, the longer the cable is, the more likely you will experience some latency.

This has the potential to occur simply because the signal has further to go. The further the signal has to go, the more likely that something will go wrong along the way.

That being said, you are very unlikely to notice the difference in speed when comparing shorter lengths of cable, like a 10 meter cable with a 20 meter cable. 

Even though the 20 meter cable is twice as long, you wouldn’t realistically be able to tell the difference.

There is a chance that you can experience some signal loss at longer lengths of cable, but it isn’t a huge issue until you have a single length that exceeds 100 meters.

A single run of Ethernet cable is designed to work up to a maximum distance of 100 meters, or 328 feet.

Beyond this, the signal will begin to weaken and has the potential to reduce the overall speed and reliability of the network connection.

If you are using an older Cat5 Ethernet cable, speeds of up to 100mbps are possible up to 100m. Anything over this and the speed will actually drop down to 10mbps.

A cable that exceeds 100 meters in length may well still work, but the likelihood of connectivity issues increases the further you push past this limit recommended by the manufacturers.

To summarise, you should be fine in terms of reliability and speed providing you keep a single Ethernet cable at less than 100 meters in length.

Just keep in the mind that the longer the cable is, the more likely you are to experience some latency.

ethernet cable

How Fast Do Ethernet Signals Travel?

It becomes clear why you don’t have to worry about the speed of an Ethernet cable that is 20 meters long compared with another that is just 10 meters long when you consider how fast the signal travels down an Ethernet cable.

The signals within an Ethernet cable travel at around two-thirds the speed light which is approximately 200 kilometers per millisecond.

There isn’t much more to really say about this to be honest.

Just make sure that you get the correct length cable and don’t worry about the minuscule difference in speed that you simply won’t notice.

How Long Should an Ethernet Cable Be?

The length of the Ethernet cable you are using really doesn’t matter, providing a single run of cable remains under 100m in length.

Any longer than this and you will likely run into some issues with signal loss given how far the signal must travel from the source to the destination.

When running Ethernet cable myself, I like to keep it as tight as possible whilst still allowing some slack at either end.

This allows for a much neater installation where the cable can be run along the floors or the walls without being a trip hazard or generally looking messy.

If you are using a network or server rack to house all your networking equipment, it is better to use shorter cables.

The reason for this doesn’t come down to a shorter cable being able to perform marginally better than a longer one, but simply to keep it looking tidy.

Using shorter cables within a rack will result in less space being taken up, less money needing to be spent on Ethernet cables, and a neater installation that makes it easier to find where everything is connected.

Although shorter cables are easily accessible and inexpensive to buy, I would suggest considering investing in a box of Ethernet cable instead.

These boxes will often come with around 1000 ft of Ethernet cable which can be terminated at whatever length you require.

If you have a need for more than just a few individual cables, a box can work out to be cheaper in the long run when you consider that a single cable that is just 5 feet in length can cost upwards of $6.

You will of course be limited to just the one color, that is unless you decide to buy more than one box, so this is something to keep in mind if you are looking to color-code your networking equipment.

If you are just needing a few Ethernet cables, it probably doesn’t warrant buying 1000 feet of cable.

There is plenty of choice available when it comes to Ethernet category, length and color. Plus you don’t need to worry about having to terminate the cable yourself either.

It really comes down to how many cables you think you’ll need and whether you want to determine the exact length of each cable as to whether a large box of Ethernet cable is worth it.

long ethernet cable

Recommended Ethernet Cables

If you are looking for some Ethernet cables for your own home network, here are some recommendations.

  • Monoprice Cat6a Cable – This cable is half the thickness of a regular Cat6a cable and comes in a variety of lengths and colors.
  • Vandesail Cat7 Cable – This cable delivers the best performance with speeds up to 10 Gbps and supports a bandwidth of 1,000 Mhz. The flat design is also space-saving.
  • Fast Cat Cat5e Bulk Cable – Buying in bulk and making your own Ethernet cables could save you money in the long run and offers more flexibility around the length of cable you need.