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Ethernet cable categories explained: Cat5e, Cat6 and Cat6a for a PC

For a home PC, the cable category rarely limits you until you pass 1 Gbps. Learn the speeds and distances each category is rated for and what else to check.

By The PC Journal7 min read

The short answer

Cat5e is rated for 1 Gbps over 100 meters, Cat6 does 1 Gbps to 100 meters and 10 Gbps over shorter runs, and Cat6a does 10 Gbps to 100 meters. For most home desks, a good Cat6 or Cat6a patch cable is plenty, and the router, switch and PC ports usually limit speed before the cable does.

What the category means

The category describes the frequency a twisted-pair cable is certified to carry, and so the speeds it supports at a given length. Cat5e is rated to 100 MHz and suits 1000BASE-T, which is gigabit Ethernet. Cat6 is rated to 250 MHz and Cat6a to 500 MHz.

For distance, the standard run for gigabit and for 10-gigabit on Cat6a is 100 meters. Cat6 can carry 10 Gbps, but only over shorter distances of about 55 meters in good conditions, which is far more than a home desk needs. Multi-gigabit speeds of 2.5 and 5 Gbps are designed to work over existing Cat5e and Cat6 cabling.

Higher categories such as Cat7 and Cat8 appear in shops. Cat8 is designed for short data-center links at 25 or 40 Gbps over about 30 meters, so it is not needed for a home PC. Cat7 is not a category recognised by the main cabling standards bodies, so a cable sold only as Cat7 deserves a closer look at its rating and construction.

Category quick reference

Ratings are for standard twisted-pair cable with RJ45 plugs. Actual speed also depends on the ports and gear at both ends.

CategoryRated frequencyTypical speedNotes
Cat5e100 MHz1 Gbps to 100 m; 2.5 Gbps supported by the multi-gig standardFine for most home gigabit links
Cat6250 MHz1 Gbps to 100 m; 10 Gbps over shorter runsA common choice for new patch cables
Cat6a500 MHz10 Gbps to 100 mThicker, often shielded; useful for longer 10 Gbps runs
Cat82000 MHz25 or 40 Gbps over short linksMeant for data centers, not home PCs

What your cable has to match

Your PC's Ethernet port speed
In Windows, open Settings, Network & internet, Ethernet to see the link speed, or check the motherboard spec for 1, 2.5 or 10 Gbps.
Your router or switch ports
Look at the label on each port or the product page. A 1 Gbps port limits the link to 1 Gbps whatever cable you use.
Cable length
Measure the path from the router or switch to the PC, including bends, and allow some slack.
Conductor material
Look for solid or stranded copper. Avoid cables marked copper-clad aluminium (CCA) for network use.
Plug and boot fit
Check that the plug fits the port and that a clip is intact so the cable seats firmly.

Compatibility notes

  • Cables of any category are interchangeable at a speed they all support. A Cat5e cable works in a Cat6 port and the link runs at the lowest rated speed.
  • Solid-core cable suits long fixed runs inside walls. Stranded cable is more flexible and suits patch cables that you move around the desk.
  • Shielded cables only help if the shield is grounded properly end to end. For a typical home run, an unshielded cable of the right category works well.
  • If a link runs at 100 Mbps when you expect 1 Gbps, try another cable and port before you change anything else, since a damaged cable or a bad plug is a common cause.

Mistakes to avoid

  • Paying for Cat8 for a home desk

    Instead: Match the cable to the ports at each end; Cat6 or Cat6a covers 1 to 10 Gbps.

  • Upgrading the cable and keeping a 1 Gbps router port

    Instead: Check every port in the path.

  • Buying the cheapest cable of unknown make

    Instead: Check it states its category and conductor material.

Where to go next

  1. How to choose a network switch
  2. How to choose a USB Ethernet adapter
  3. How to choose a gaming router
  4. Powerline Ethernet explained

Sources

  1. Telecommunications Industry AssociationTIA · Reference

This guide explains a decision process. It does not contain product rankings, benchmark results or hands-on measurements. How we research

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