How Far Can You Use Ethernet Cable?

The primary concern of most people installing Ethernet cabling is the maximum segment length. In short, the answer is 100 meters from origin to destination, or about 328 feet. This is approximately the length of one football field. The limiting factor is the timing of Ethernet signals, making it a number that will not vary from cable to cable; all Ethernet-carrying cables (such as Cat-5 and Cat-5e) will have this same limitation.

Though the maximum distance of Ethernet cabling is 100 meters from origin to destination, this includes patch cables. A stand-alone cable without patch cords or cross-connect jumpers is only 90 meters (295 feet). This distance, without additional wires, is referred to as the horizontal link. In most situations, the horizontal link will be the segment of cabling that runs in the wall between a telecommunications room and a wall outlet in the workspace.

After the 90 meters running through the walls, an additional 10 meters (33 feet) is allotted for the wires that connect from your wall outlet to your computer or from electronic equipment in the telecommunications room to the horizontal link. In total, the combined length of these two segments must not exceed 10 meters, unless the horizontal link totals less than 90 meters, in which case the patch cords and cross-connect jumpers can be extended to a maximum of 20 meters (66 feet).

The total maximum of 100 meters is referred to as the horizontal channel. For example, a complete horizontal channel might include 6 meters of cross-connect cables and patch cords from the origin of Ethernet signals in a business, run 90 meters through the wall and end at a wall outlet where 3 meters of patch cables connect a working PC to that outlet. The same principles may be applied to a home scenario, including a modem, router and network.