Category 5 and Category 6 are both 100 meters, and the regular oxygen-free copper Category 6 wire can reach about 120 meters. If you want to increase the transmission distance, you can install a repeater between the two twisted pairs, and you can install a maximum of 4. Fiber optic cable can be run anywhere from 300 meters up to 80 kilometers (roughly 50 miles) depending on the cable type, transceiver used, and network standard. For most enterprise or data center applications using multimode fiber, the practical limit sits between 300 m and 550 m. Due to the small core, only one optical mode is allowed to be transmitted. Key single mode distance specifications:. This guide dives deep into the maximum length constraints of the three most common network cables—Ethernet, coaxial, and fiber optic—explaining why these limits exist, how they vary by cable type, and how to extend them when needed.