Does Cat5 Cable Length Affect Internet Speed?

By Shea Laverty

One of the biggest draws in maintaining a wired network as opposed to wireless is the ability to maintain network speed despite interior infrastructure and interference. In most applications, Category 5, or Cat 5, Ethernet cables are the standard choice. While in most cases, cable length won't affect the speed of data transmission between devices or over the Internet, excessive lengths can cause problems.

Under 100 Meters

The maximum connection length for Cat 5 cables without loss of transfer speed is 100 meters, or 328 feet. Cables at or under this length generally don't experience performance loss. Most Cat 5 cables don't extend to this length, and are instead available in varying lengths under 100 feet.

Over 100 Meters

Cat 5 cables that extend beyond 100 meters in length run the risk of diminished performance. This is because data is sent along these cables in "packets," and extended lengths increase the likelihood of packet loss. Transmissions errors also become more likely as cable length extends beyond the maximum. As a rule of thumb, if you require cables to reach beyond 100 meters, consider multiple cables and repeater devices.


A repeater is a device that bridges the gap between two segments of cable. Repeaters re-time and regenerate the data transmission signals to the correct amplitudes before sending them along the next segment of cable. This can reduce packet loss and transmission error compared to using extremely long cables, however it is not a perfect solution. Repeaters cause minor delays themselves, as time is required to properly regenerate the signal. This delay increases based on the number of repeaters used to connect a single line of network cables.


In most non-enterprise situations, it's extremely unlikely you'll ever need to use a Cat 5 cable in excess of 100 meters. Even this length will be excessive in most household applications, where devices will be fairly close to one another. In enterprise situations, using repeaters may be a better choice than cables that exceed 100 meters in length. However, your network administrator will have to determine a cable layout that will minimize repeater use, which will in turn minimize network delay.