Ethernet Cable Ratings, Speed Chart, and Wire Colors

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Ethernet cable ratings describe the performance category of a cable, while jacket and shielding markings describe where and how it can be installed. Conductor colors identify the pinout; they do not indicate speed or cable category.

For most home and office networks, Cat5e supports 1Gbps to 100 meters, Cat6 supports 10Gbps over shorter runs, and Cat6A supports 10Gbps to the full 100-meter channel limit. Actual results depend on the Ethernet standard, cable length, connectors, patch panels, bend radius, crosstalk, and installation quality.

Ethernet cable ratings: choose a category for your network

The category printed on the cable jacket—such as Cat5e, Cat6, or Cat6A—indicates electrical performance requirements. It is not a guarantee that every device will operate at the category’s headline speed. Network ports, transceivers, channel length, and termination quality also determine the result.

  • Cat5e: The practical baseline for gigabit Ethernet. It supports 1000BASE-T to a 100-meter channel and can support 2.5Gbps, and in suitable installations 5Gbps, using NBASE-T standards.
  • Cat6: Provides more performance margin against crosstalk than Cat5e. It supports 1Gbps, 2.5Gbps, and 5Gbps to 100 meters. 10Gbps is generally limited to approximately 55 meters, depending on the channel and alien-crosstalk conditions.
  • Cat6A: The usual copper choice for 10GBASE-T to 100 meters. Its larger conductors, separators, or other construction features help control crosstalk, but the cable still requires compatible connectors and proper installation.
  • Cat7: An ISO/IEC category commonly used with shielded construction and rated for 10Gbps-class links to 100 meters. Connector systems and regional standards vary, so a Cat7 cable does not automatically create a Cat7-compliant channel when installed with ordinary components.
  • Cat8: Intended for high-bandwidth data-center links, including 25Gbps and 40Gbps Ethernet over channels up to 30 meters. It is normally shielded and is rarely necessary for a standard home or office run.

For a new building run, Cat6A is usually the safer selection when 10Gbps service may be needed at the full channel distance. For ordinary gigabit access points, computers, televisions, and switches, properly installed Cat5e or Cat6 is generally sufficient. A higher category cannot increase the speed of a device with a slower network port.

Ethernet cable speed chart: speed, distance, and channel limits

The following Ethernet cable speed chart shows representative maximums for common twisted-pair applications. The distances refer to the complete channel unless stated otherwise. A standards-based channel normally includes up to 90 meters of permanent cable plus up to 10 meters of patch cords.

  • Cat5e — 1000BASE-T: 1Gbps up to 100 meters.
  • Cat5e — 2.5GBASE-T: 2.5Gbps up to 100 meters when the cable, connectors, and installed channel meet the required performance.
  • Cat5e — 5GBASE-T: Up to 5Gbps over 100 meters may be supported by a suitable channel, but performance is more sensitive to cable quality, bundling, and crosstalk than ordinary gigabit operation.
  • Cat6 — 1GBASE-T, 2.5GBASE-T, or 5GBASE-T: Up to 100 meters under compliant channel conditions.
  • Cat6 — 10GBASE-T: Commonly up to 55 meters. The usable distance can vary with cable construction, patch cords, connector quality, and alien crosstalk from nearby cables.
  • Cat6A — 10GBASE-T: Up to 100 meters for a compliant channel, including the permanent link and patch cords.
  • Cat7 — 10Gbps-class Ethernet: Up to 100 meters in a properly designed compatible channel.
  • Cat8 — 25GBASE-T or 40GBASE-T: Up to 30 meters, typically for short data-center connections.

These figures describe Ethernet applications, not a universal speed promise for the cable alone. A 100-meter Cat6A channel carrying 10Gbps requires the right category-rated jacks, patch panels, patch cords, and terminations. Excessive untwisting at the jack, sharp bends, poor punchdowns, damaged cable, or dense parallel bundles can reduce performance.

Short patch cables also need the appropriate construction. Stranded patch cable is flexible but has greater electrical loss than solid horizontal cable, so the complete channel—not just the cable printed with the highest category—must remain within the applicable limits. A network link will normally negotiate to the highest speed that both endpoints and the channel can reliably support.

Read jacket, shielding, conductor, and certification markings

Jacket and shielding labels

Jacket markings describe fire, smoke, environmental, and shielding properties. They are separate from the Cat rating.

  • CM: General-purpose communications cable for locations where stricter riser or plenum rules do not apply.
  • CMR: Riser-rated cable intended for vertical runs between floors. It is not a substitute for plenum cable where air-handling spaces require plenum approval.
  • CMP: Plenum-rated cable for spaces used to move environmental air, such as some ceiling plenums. It uses a lower-smoke, more fire-resistant jacket construction.
  • CMX: Limited-use cable, often found in residential or restricted applications. Local building rules determine where it is acceptable.
  • LSZH: Low-smoke, zero-halogen jacket material. It may be preferred in transport, industrial, or enclosed installations, but LSZH is not the same as CMP or CMR.
  • Outdoor, sunlight-resistant, wet-location, or direct-burial: Environmental ratings for exposure to ultraviolet light, moisture, or soil. Outdoor-rated cable may use a water-blocking layer, UV-resistant jacket, or gel, but each marking should be checked for the intended installation.

Shielding is commonly shown with a notation such as U/UTP, F/UTP, or S/FTP. The first character describes the overall cable shield, and the second describes shielding around each twisted pair.

  • U/UTP: No overall shield and no individual pair shields. This is the common unshielded construction.
  • F/UTP: An overall foil shield around otherwise unshielded pairs.
  • U/FTP: No overall shield, but each pair has its own foil shield.
  • S/FTP: An overall braided shield with foil around each pair.
  • SF/UTP: Overall braid and foil, with unshielded individual pairs.

Shielded cable works as part of a shielded channel. Shielded plugs, jacks, patch panels, and correct bonding are needed to maintain the shield. Installing shielded cable with unshielded components does not provide the intended protection against electromagnetic interference.

Conductor material and cable certification

Solid bare copper conductors are normally used for permanent horizontal runs because they provide stable electrical performance and terminate well on punchdown contacts. Stranded copper conductors are more flexible and are normally used for patch cords. The cable and connector must be suitable for the conductor type; a stranded patch cord should not automatically be used in place of solid horizontal cable.

CCA, or copper-clad aluminum, uses an aluminum core with a thin copper coating. It is less desirable for structured Ethernet cabling because its resistance and mechanical properties differ from solid copper. CCA products may not meet the performance, safety, or code requirements expected of category-rated premises cable. A cable marked as Cat5e or Cat6 should be checked for solid copper conductors rather than relying on the category label alone.

Markings may also show conductor size, such as 23 AWG or 24 AWG, temperature limits, voltage ratings, manufacturer information, and standards references. Larger conductors can reduce resistance but may require compatible jacks and plugs. The cable category, jacket rating, and conductor material should all match the installation.

Certification has several meanings. A safety listing from organizations such as UL or ETL addresses applicable construction and fire requirements; it does not by itself prove that an entire installed link will deliver a particular Ethernet speed. Category performance depends on the cable, connectors, patch panels, and workmanship together. For important installations, certification testing with a qualified cable analyzer can verify wiremap, insertion loss, return loss, and crosstalk for the completed channel.

T568A and T568B Ethernet wire colors: order and plug orientation

T568A and T568B are two approved termination schemes for the eight conductors in an RJ45-style Ethernet connection. The schemes use the same four twisted pairs but place the green and orange pairs in different positions. Ethernet colors identify pin order, not speed, category, or shielding.

To read either order, view the plug from the contact side with the gold contacts facing up and the locking latch underneath. Read pins 1 through 8 from left to right. Keep each pair twisted as close as practical to the termination; excessive untwisting can increase crosstalk.

T568A color order

  1. White/green
  2. Green
  3. White/orange
  4. Blue
  5. White/blue
  6. Orange
  7. White/brown
  8. Brown

T568B color order

  1. White/orange
  2. Orange
  3. White/green
  4. Blue
  5. White/blue
  6. Green
  7. White/brown
  8. Brown

A straight-through patch cable uses the same scheme at both ends: T568A-to-T568A or T568B-to-T568B. A crossover cable uses T568A at one end and T568B at the other, swapping the transmit and receive pairs. Most modern switches and network adapters support auto MDI-X, so a crossover cable is rarely required, but consistent straight-through wiring remains the normal choice.

For a structured installation, the patch panel and wall jack should follow the same selected scheme. The labels on many jacks show both A and B rows; follow only one row for all terminations. A cable tester can detect reversed pairs, split pairs, opens, and shorts—faults that may not be visible from the colors alone.