The Quick and Dirty Route to Extra Long Ethernet Cables

by Tom Harrison in hardware

Before WiFi was everywhere, this is how my roommates and I wired our college apartment with CAT5 cable to 3 desktop computers and an XBox, all very far away from where the cable guy installed our router. All done with a cheap spool of cable and without a crimping tool.


We ran into an interesting problem whilst in college: three desktop computers without wireless network cards were spread out to the far corners of our apartment, with the network router located at a central point that was further away than any of our ethernet cables could possibly reach. Extra-long store bought ethernet cables are very expensive and besides, we had been given a giant spool of cat 5 cable for free. The only problem was that we couldn’t attach the RJ45 connectors without a crimping tool, and saw the price tag for either renting or buying a crimper as unreasonable, given that it would only be for one-time use. There had to be a better (read: free) way of doing this.

Indeed there was a more cost efficient method of getting our desktops online – splice our lengthy, uncut cat 5 cable with our existing store bought ethernet cables. Once this solution hit us, the hardest part of the task was stringing the cable around the house and out of the way. Here’s our guide quick and dirty guide to assembling extra-long ethernet cable:

How to assemble your extra-long ethernet cable

  1. Measure out the distance between your computer and router and then cut an equally long length of cat 5 cable. Make sure to go a little longer than the distance you need so that you have a bit of slack in the cable.
  2. Take your insufficiently long store bought ethernet cable and cut it in half. Use the shortest one you can find since all you want are the end pieces with the RJ45 connectors, not the length between them.
  3. Splice each of the halves that you just cut onto either end of the cat 5 cable that you measured out in step 1.
  4. Jack into your router using your brand new, extra-long ethernet cable.

How to actually splice your ethernet cables together

Step 3, “Splice each of the halves that you just cut…” is a short sentence, but encompasses most of the work in this process. In order to splice these wires properly you will need a two things:

  • A small, sharp knife such as an exacto knife or a pocket knife
  • Electrical tape

Caution! None of the wires you are splicing should be plugged into anything at this point. You do not want to electrocute yourself.

Caution! Knives, especially small craft knives like the exacto knife, are extremely sharp. Use them with caution. You do not want to cut yourself.

So, you’ll be starting out with one extra long length of cat 5 cable, and two short halves of an ethernet cable that you’ve previously cut in half.

A short cable, cut in half

Use the exacto knife to cut away part of the thick sheath that encases each of your ethernet cables. By doing this, you will reveal the individual wires inside. Each of these wires is protected by its own separate sheath, and each one is a different color.

The main sheath cut away

Again, use the exacto knife to reveal the copper wire inside each of the multi-colored sheaths. Take the end of cable with the RJ45 connector and attach it to the end of the extra-long cat 5 cable by twisting together each individual wire with it’s like-colored counterpart.

The cables twiested together

Use the electrical tape to insulate each of the wires that you twisted together.

Insulating the individual wires

Finally, gather everything together and insulate the entire exposed area with electrical tape.

Insulate the main wire

Now you have yourself an extra-long length of ethernet cable that you didn’t have to shell out $40 or more for, and you didn’t have to go buy a crimping tool assemble cat 5 cable and RJ45 connectors. There may be more thorough ways of splicing your wires (such as sodering), but this is the quick and dirty method that we used to get the job done, and it worked.