TradesHow this works
Enter the run length, the speed you need, and whether the path is a normal indoor run or goes between buildings or through heavy interference. The tool lays copper, multimode fiber, and single-mode fiber side by side, marks which ones can actually carry the link, and recommends the cheapest media that works.
The two hard walls are the 100 meter copper channel limit and the fact that copper hates electrical noise. Inside those, copper wins on cost and simplicity and carries Power over Ethernet. Outside them, past 100 meters, between buildings, or in strong EMI, fiber is the answer.
Common questions
How far can copper Ethernet run?
The twisted-pair channel limit is 100 meters, about 328 feet, for any category. That is roughly 90 meters of horizontal cable plus 10 meters of patch cords. Past 100 meters, no copper category will carry the link reliably, and you move to fiber.
What cable do I need for 10 Gigabit?
Cat6a carries 10 Gbps to the full 100 meters. Cat6 can do 10 Gbps but only to about 55 meters, so it is fine for a short run and not a long one. Cat5e and Cat6 carry 1 Gbps to 100 meters. Above 10 Gbps at any real distance, you want fiber.
When should I use fiber instead of copper?
Use fiber when the run is over 100 meters, when it goes between buildings, when the path has strong electrical interference or lightning exposure, or when you need speeds above 10 Gbps over distance. Fiber is immune to interference and does not tie two buildings to a shared ground.
What is the difference between multimode and single-mode fiber?
Multimode fiber, OM3 or OM4, is cheaper and reaches to about 300 to 400 meters at 10 Gbps, good for backbones inside and between nearby buildings. Single-mode reaches tens of kilometers and scales to the highest speeds, the choice for long campus and metro runs, at a higher cost per link.
Can I mix fiber and copper?
Yes, and most networks do. The common design is copper to the powered edge devices, since it is cheap and carries Power over Ethernet, and fiber in the backbone between closets and buildings, where distance and interference rule copper out. This tool picks the right media for one run at a time.
Sources: Copper channel limit 100 m (328 ft); Cat5e/Cat6 1G, Cat6a 10G to 100 m, Cat6 10G to ~55 m (TIA/ISO; ShowMeCables, EDGE Optical) · Multimode OM3 10G to ~300 m, OM4 to ~400 m; single-mode tens of km; fiber for between-building/EMI runs (FS.com). Engine version 1.0.0. Risk tier 1.