What is the maximum Ethernet cable length?

For the conventional balanced-copper applications covered here, the usual structured-cabling channel is up to 100 meters total, commonly composed of up to 90 meters of fixed permanent-link cabling plus patch and equipment cords. The cable category and Ethernet application still have to be compatible.

Can Cat5e run 1 gigabit Ethernet?

Yes. 1000BASE-T is specified for a compliant four-pair Category 5e channel up to 100 meters. Both link devices must support the rate and the installed channel must meet its applicable requirements.

Can Cat5e run 2.5 or 5 gigabit Ethernet?

IEEE 802.3bz defines 2.5GBASE-T and 5GBASE-T operation over 100-meter Category 5e or better channels that meet the applicable signal-to-noise requirements. Existing or noisy Cat5e installations may require qualification and can negotiate down.

How far can Cat6 run 10 gigabit Ethernet?

Published TIA TSB-155 guidance says 10GBASE-T should operate over Category 6 channels up to 37 meters and may operate from 37 to 55 meters depending on the alien-crosstalk environment. Field qualification is required; Category 6A is the normal choice for a 100-meter 10GBASE-T design.

How far can Cat6A run 10 gigabit Ethernet?

A compliant Category 6A channel is designed to support 10GBASE-T up to 100 meters, subject to compliant components, installation and testing.

Do patch cords count toward Ethernet distance?

Yes. The Ethernet channel includes the fixed cabling, connectors, patch cords and equipment cords between the two active devices. This checker adds the entered patch-cord total to the fixed cable length.

Does passing this checker certify an Ethernet link?

No. Length and category alone cannot verify insertion loss, return loss, crosstalk, alien crosstalk, termination quality, component compliance, electromagnetic noise or device support. Certification requires appropriate field testing and project criteria.

Ethernet Cable Distance and Speed Checker

Check whether a Cat5e, Cat6 or Cat6A copper channel is within published reach guidance for 100 Mb/s, 1 Gb/s, 2.5 Gb/s, 5 Gb/s or 10 Gb/s Ethernet.

Private and client-side: entered lengths never leave your browser. This is a design screen, not cable certification or a guarantee of link speed.

Cable channel inputs

Use the lowest category rating among the cable, jacks, patch panels and cords.

Cable category The complete channel is limited by its lowest-rated part.

Target Ethernet speed Both network ports must advertise this rate.

Length unit Changing units converts the entered values.

Fixed cable length (m) Installed horizontal or permanent-link cable.

Patch cords, total (m) Add cords at both active-device ends.

Distance and speed screen

Enter valid values

The complete channel length will be compared with the selected cable and Ethernet application.

Complete channel length-

Published reach used-

Distance remaining-

Highest screened rate-

Secondary unit-

Channel details

Selected application-

Cable category-

Fixed cable screen-

Qualification note-

How the Ethernet distance check works

The checker adds the installed fixed cable and all patch/equipment cords to form the end-to-end copper channel:

Channel length = fixed cable length + total patch-cord length

That total is compared with the application/category guidance below. A conventional 100 m structured-cabling channel is commonly designed as no more than 90 m of permanent-link cabling plus up to 10 m of cords. Cord gauge, temperature, bundles and project rules can require more restrictive designs.

Application	Cat5e	Cat6	Cat6A
100BASE-TX	100 m	100 m	100 m
1000BASE-T	100 m	100 m	100 m
2.5GBASE-T	100 m*	100 m*	100 m
5GBASE-T	100 m*	100 m*	100 m
10GBASE-T	Not screened	37 m baseline; 37–55 m conditional†	100 m

* IEEE 802.3bz operation requires the channel to meet its applicable signal-to-noise criteria. † Existing Cat6 suitability depends on alien crosstalk and other channel measurements; passing a length threshold alone is insufficient.

What length cannot tell you

Infrastructure limit: this checker does not certify cabling or predict real file-transfer throughput. Use a suitable field certifier and the current project, cabling-system and equipment requirements before relying on a link.

A link can fail below the nominal distance because of poor terminations, split pairs, damaged cable, noncompliant components, excessive untwist, return loss, insertion loss, internal or alien crosstalk, heat, electromagnetic interference, or unsupported port speeds. It can also establish a physical link while application throughput is lower because of protocol overhead, endpoint limits, congestion or errors.

Cat6 at 10 Gb/s

Cat6 is deliberately shown as a qualification case. TIA TSB-155 guidance cited by Fluke says 10GBASE-T should operate up to 37 m and may operate from 37 m to 55 m depending on the alien-crosstalk environment. New 100 m 10GBASE-T designs normally use Cat6A.

Standards basis and sources

IEEE P802.3bz 2.5/5GBASE-T Task Force — project approval and public project material.
Ethernet Alliance archive: NBASE-T PHY Specification 2.3 — 2.5/5GBASE-T cabling and signal-to-noise basis.
Ethernet Alliance: 10GBASE-T overview — Category 6 and Category 6A link-segment guidance.
Fluke Networks: 10GBASE-T field testing requirements — TIA TSB-155 Cat6 qualification explanation.

This page summarizes public application guidance; it does not reproduce or replace IEEE, ANSI/TIA, ISO/IEC, manufacturer or project standards. Always use the version adopted for the installation.

Ethernet cable distance FAQs

Is 100 m the same as 328 ft?

Approximately. Exactly 100 m is 328.084 ft. The checker calculates internally in meters and displays a rounded secondary-unit value.

Should I enter cable length or straight-line distance?

Enter the actual cable pathway, including rises, drops and service loops, then add the real patch cords at both ends. Straight-line distance can understate the channel.

Can Cat5e run 5 Gb/s?

It can under IEEE 802.3bz when the 100 m channel meets the applicable signal-to-noise requirements and both devices support 5GBASE-T. Because existing Cat5e conditions vary, the checker marks this as a qualification case.

Why does Cat6 10 Gb/s need extra caution?

At 10GBASE-T frequencies, noise coupled from neighboring cables can be decisive. Length alone cannot establish alien-crosstalk performance.

Does a Cat6A cable make every part Cat6A?

No. A channel is constrained by its lowest-rated component, including jacks, patch panels, couplers and patch cords, as well as workmanship.

What if the result is over the limit?

Shorten or redesign the copper channel, relocate active equipment, use a suitable intermediate switch where the environment permits, or consider fiber for longer building or campus links. Do not add an unplanned passive coupler to solve distance.