How to Make a LAN Cable at Home: Step-by-Step Guide with Color Codes (T568A & T568B), Tools and Any Length
Build a perfect-length Ethernet cable in about 10 minutes. Includes pin-by-pin colour charts, crimping technique, testing, expert tips and a troubleshooting table.
Time needed | Difficulty | Cable types | Max length |
|---|---|---|---|
≈ 10 minutes per cable | Beginner-friendly | Cat5e, Cat6, Cat6a | 100 m (328 ft) |
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In this guide
What you need (tools and materials)
Choosing the right cable type and length
T568B vs T568A colour code charts
10 steps to crimp your cable
Testing, expert tips and common mistakes
Troubleshooting table and FAQ
Why Make Your Own LAN Cable?
Ready-made Ethernet cables are rarely the right length. They are either too short to reach the router or so long that a coil of excess wire sits behind your desk, collects dust and hurts airflow. Making your own solves both problems: you cut the cable to the exact length you need, choose the quality of cable and connectors, and can repair a damaged plug in minutes instead of throwing the whole cable away.
With a few inexpensive tools and the colour chart in this guide, a beginner can build a reliable, gigabit-ready cable on the first or second try. Follow the steps in order and test at the end.
What You Need (Tools and Materials)
Figure 1: Tools and materials for making an Ethernet cable.
Item | Purpose | Notes |
|---|---|---|
Bulk Ethernet cable | The wire itself | Cat5e for most homes; Cat6 for faster or future-proof setups |
RJ45 (8P8C) plugs | Plugs on each end | Must match cable type (Cat5e vs Cat6, solid vs stranded) |
RJ45 crimping tool | Presses the plug onto the wires | Most also strip and cut the cable |
Cable stripper / cutter | Removes the outer jacket | A crimper with a built-in blade works |
LAN cable tester | Checks all 8 wires | Strongly recommended, not optional for beginners |
Boots (optional) | Strain relief, neat finish | Slide on BEFORE crimping |
Flush cutter / scissors | Trims wires evenly | A clean square cut is essential |
Beginner tip: pass-through plugs
Pass-through RJ45 plugs let the wires slide all the way through the plug, so you can see the colour order before crimping. They need a crimper that supports them (it will usually have a blade for trimming the wire ends flush).
Choose Your Cable Type
Category | Typical speed | Best for | Notes |
|---|---|---|---|
Cat5e | Up to 1 Gbps | Everyday home and office | Most affordable and widely used |
Cat6 | 1 Gbps (10 Gbps up to about 55 m) | Gaming, streaming, future-proofing | Thicker cable, use Cat6 plugs |
Cat6a | 10 Gbps up to 100 m | Heavy-duty and professional setups | Stiffer, often shielded |
Solid vs stranded: Solid-core cable suits permanent runs (inside walls, along baseboards). Stranded cable is more flexible and better for patch cables you will move around. Use plugs made for the type you buy.
How Long Can Your LAN Cable Be?
One of the best reasons to make your own cable is that you control the length. The maximum for a single Ethernet run is 100 metres (328 feet), including the patch cables at each end.
Figure 2: Measure the route the cable will actually take, not the straight line.
Measure the real path, including corners and going up or down walls.
Add 30–50 cm (1–1.5 ft) of slack at each end so you can re-terminate later if a plug fails.
Cut with a clean, straight cut.
Formula: Total cable length = measured route + about 1 m of slack.
The LAN Cable Colour Code: T568B vs T568A
Inside every Ethernet cable are four twisted pairs (eight wires). The order in which they sit inside the RJ45 plug matters. There are two standards; both perform identically, but you must use the same one on both ends of a normal cable.
Figure 3: T568B (recommended) and T568A pin-by-pin colour charts.
Figure 4: Correct plug orientation: clip down, open end facing you, pin 1 on the left.
Pin | T568B (recommended) | T568A |
|---|---|---|
1 | White/Orange | White/Green |
2 | Orange | Green |
3 | White/Green | White/Orange |
4 | Blue | Blue |
5 | White/Blue | White/Blue |
6 | Green | Orange |
7 | White/Brown | White/Brown |
8 | Brown | Brown |
Which one should you use?
Straight-through cable (router to PC, switch to PC): the same standard on both ends. T568B on both ends is the safest choice.
Crossover cable (PC to PC, very old switch to switch): T568A on one end and T568B on the other. Modern devices with Auto-MDIX do not need crossover cables.
Memory trick: In T568B, pins 1–2 are orange and pins 3 and 6 are green. Blue and brown always stay on pins 4–5 and 7–8.
Step-by-Step: How to Make a LAN Cable
Step 1: Measure and cut the cable
Measure your route, add the slack, and cut the cable cleanly. A ragged cut makes the wires harder to insert later. (See Figure 2 above.)
Step 2: Slide on the boot (optional)
Figure 5: Slide the boot onto the cable before you crimp.
If you are using boots, slide one onto the cable now, wide opening facing the cable end. It is very easy to forget this and have to cut off a finished plug.
Step 3: Strip the outer jacket
Figure 6: Strip about 2.5–3 cm (1–1.2 in) of outer jacket.
Remove about 2.5–3 cm (1–1.2 in) of the outer jacket. Use the stripper slot on your crimper and rotate gently around the cable once. Do not cut into the wires. If you nick the copper, trim the end off and strip again.
Step 4: Untwist and straighten the pairs
Figure 7: Untwist only the exposed part of each pair.
Separate the four pairs and trim off any thin plastic spine or pull string.
Untwist each pair only as far as needed and straighten the wires between thumb and finger.
Keep the untwisted length as short as you can, ideally under 1.3 cm (½ in).
Step 5: Arrange the wires in colour order
Figure 8: Lay the eight wires flat in T568B order.
Line the wires up side by side in this order and keep them tightly together:
White/Orange, Orange, White/Green, Blue, White/Blue, Green, White/Brown, Brown
Step 6: Trim the wires evenly
Figure 9: Cut all eight wires square, leaving about 1.2 cm above the jacket.
Cut the wire tips in one straight line, leaving about 1.2 cm (½ in) of wire above the jacket. For pass-through plugs, trim after the wires emerge from the front.
Step 7: Insert into the RJ45 plug
Figure 10: Push every wire to the end of the plug, jacket inside the plug body.
Hold the plug with the clip facing down.
Push the wires in gently until each one reaches the end of its channel.
Look at the front: you should see eight copper tips touching the end.
The outer jacket should go about 5 mm inside the plug so the strain relief can grip it.
Step 8: Crimp
Figure 11: Squeeze fully until the tool clicks or the ratchet releases.
Place the plug in the matching slot of the crimper and squeeze firmly and completely. The gold contacts should now sit pressed down into the wires. Check that the plug does not slide on the cable when you gently tug it.
Step 9: Repeat on the other end
Figure 12: Straight-through vs crossover wiring.
For a normal cable, repeat Steps 3–8 using the same standard (T568B) on the second end.
Step 10: Test your cable
Figure 13: A good cable lights 1 through 8 in order on both units.
Plug each end into a LAN tester and switch it on. The lights should step through 1 to 8 in order on both units. If any light is skipped, out of order, or lit together with another, see the troubleshooting section.
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Expert Tips for a Clean, Reliable Cable
Figure 14: Six habits that make homemade cables reliable.
Keep the twist. Untwisting more than about 1.3 cm per pair adds crosstalk and can cut speed.
Match your parts. Cat6 plugs for Cat6 cable; solid-core plugs for solid cable and stranded plugs for stranded.
Avoid sharp bends. Do not bend the cable tighter than roughly four times its diameter.
Keep it away from power. Long parallel runs next to mains cables can add noise.
Label both ends. Room name plus port number saves hours later.
Use quality plugs. Cheap plugs are a common source of intermittent faults.
Test every time. A cable that seems fine can still fail at gigabit speed.
Beware split pairs
A split pair happens when two wires from different twisted pairs end up on pins 3 and 6 (or 1 and 2). The pin order may look sensible and a basic continuity tester can pass it, yet speeds drop and errors appear. Following the colour chart exactly avoids this problem.
Common Mistakes to Avoid
Mistake | What to do instead |
|---|---|
Forgetting the boot | Slide boots on before you crimp the first plug. |
Reusing a crimped plug | Plugs cannot be reused. Cut it off and fit a new one. |
Mixing T568A and T568B on one cable | Use the same standard on both ends unless you need a crossover. |
Cat6 cable with Cat5e plugs | Use plugs rated for your cable. Cat6 wires are thicker. |
Not pushing wires all the way in | Check eight copper tips are visible at the end before crimping. |
Skipping the tester | Always test; many faults are invisible by eye. |
Troubleshooting Common Problems
Figure 15: How to read your cable tester.
Problem | Likely cause | Fix |
|---|---|---|
Tester light skips a number | A wire is not touching its contact | Re-crimp; if it persists, cut off the plug and redo it |
Lights show out of order | Wrong colour order | Cut off the plug and re-terminate with the correct pin order |
Two lights flash together | Two wires touching (short) | Cut off and redo, keeping wires separate and trimmed square |
No lights at all | Wire not inserted fully, or a broken cable | Check the plug is seated in the tester, then re-crimp |
Works but only 100 Mbps | Poor crimp or split pair | Re-terminate and follow the colour chart exactly |
Plug pulls off easily | Jacket not inside the plug | Re-strip to the correct length and recrimp |
Stuck? Ask for help at Fixspert
Network still unstable after replacing the cable? The fault may be the router, switch, Wi-Fi or ISP line. An IT expert can check it for you.
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Frequently Asked Questions
Is it cheaper to make your own LAN cable?
Yes, especially for long or custom lengths. Bulk cable and plugs cost less per metre than ready-made cables, and you only buy the tools once.
T568A or T568B, which is better?
Performance is identical. T568B is more common, so use it for consistency. What matters is using the same standard on both ends.
Can I make a LAN cable without a crimping tool?
It is not recommended. A screwdriver can force a plug shut, but the contacts rarely seat properly. A basic crimper is inexpensive.
How long can a LAN cable be?
Up to 100 metres (328 feet) for standard Ethernet, including patch cables.
Why is my homemade cable not working?
Usually the wires are not fully inserted, the colour order is wrong, or the crimp is poor. Retest with a cable tester.
Can I reuse an RJ45 plug?
No. Crimping presses the contacts into the wires. Cut it off and use a new plug.
Does Cat6 need special plugs?
Cat6 cable is thicker, so use plugs designed for Cat6 or the wires may not fit properly.
Final Thoughts
Making your own LAN cable is one of the most useful skills for a home network. Once you know the colour order, strip carefully and test every cable, you can build clean, reliable cables of any length in minutes. Start with a short practice cable and you will soon be wiring your whole home neatly.
Was this guide helpful? Share it with someone setting up a home network, and leave a comment if you got stuck on any step.
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