"I can"t really finish my basement on my own, because I don"t know how to do electrical stuff. I don"t even know what wire to buy!"

You say "stuff" because you really don"t have a clue what it"s all about.

You are watching: Difference between 12 2 and 12 3 wire

Well... I would say back to you - "That"s a really lame excuse." You haven"t even investigated it yet.

You haven"t read an article like this that reveals to you this 1 simple fact:

You only need 3 wire types:

14/2 - The White Wire - used for wiring lights and light switches

12/2 - The Yellow Wire - used to wire plugs

14/3 - Same as 14/2 but with an extra red wire in it so you can control the same lights with 2 different switches (like for hallways and stairs)

THAT’S IT! That"s all you really need to know!

What Does It All Mean Though?

Here"s a standard 14/2 strand of Romex electrical wire


Both 14/2 and 12/2 wire types have 3 wires wrapped in "sheathing". Yellow sheathing for the 12 gauge. White sheathing for the 14 gauge.

Wire 1:  The white wire. This is the neutral wire.

Wire 2: The black wire. This is the "hot" wire.

The copper wire, this is the ground wire. (they don"t count this one, hence the 2 instead of 3)

All of the wires are made of copper but two of them are coated in white or black insulation because they actively carry an electrical charge. It"s kind of stupid but because of this "they" ignore the grounded wire when counting them… thus 12/2 and 14/2 instead of 14/3 or 12/3. Sometimes the ground has brown paper sheathing around it, other times not. (I don"t know why.)

12 gauge wire (the yellow one) is thicker than 14 gauge. Since it"s thicker it can handle more "load". Because things that you plug-in like TVs, stereos, etc. tend to use more electricity than light bulbs, plugs are typically wired with 12 gauge. You could also wire your plugs with 14/2 if you wanted to. (assuming your local code allows for it)

Technically you could also wire your lights with 12 gauge wire. The only problem is it"s thickness makes it really hard to work with. Twisting it can be difficult and with lights and light switches, there"s a lot of twisting, sometimes 3 or 4 wires together.

Professionals - maybe you guys do that all the time? Little baby hands like me, I go with 14 gauge (the white wire) for my light circuits.

Here"s what I did to wire my basement:

Once I got the hang of it I ran the wiring for all the plugs and lights. Nothing was hooked up. I just ran it back to the wiring panel and let it hang there.


Can I tell you something that is going to completely blow your mind?


You can wire your basement and pass your electrical inspection without ever turning on the power.

BOOM! Say what?

How does the inspector know you wired your basement correctly? They just need to see that it was wired correctly. If you did it right, you can move-on to drywall. They"ll check light switches and plugs in the final inspection.

Listen, hopefully this article gets you going in the right direction. You"ll still have to read a couple of books and spend a few weekend wrapping your brain around the basics concepts of electricity. But once you get that part down you are golden.

It"s Just Wire

We"ll need another article to cover how to run electrical wire. Plus, I want to cover the type of things that inspectors are want to see. For now, remember these 2 things:

You can run your own electrical and pass inspection without ever turning on a light or hooking up a plug.Finishing your basement requires three types of wire. 14/2 (lights), 14/3 (lights with 2 switches) and 12/2 (plugs).
NOTE: If you are planning to have a sauna, microwave, dishwasher or professional workshop in your basement you"ll need some other wire types as well. We"ll cover that in another article.

If you"re going to your local Home Depot or some other hardware store this may be your first time in the electrical section. Don"t freak out.

There"s a lot of stuff that you"ve never seen. Just remember what you need - 14/2 - White, 12/2 - Yellow, 14/3 - White. If you want to start small get a 100 feet. But if your basement is a thousand square feet or more you should go ahead and buy the 250 ft roll.


Some people may call it Romex. Romex is the Trademarked BRAND name of Type NM cable invented by the Rome Wire Company. That"s what we"ve been talking about.

Good luck on your project. I hope you"ll consider trying electrical (if your area allows it), it"s really fun and you can do it!

Cheers - Jason

Need More? Check out These Other Resources

1. Go back to how to wire a basement main page

2. Do you need some electrical books? Here"s what I used.

See more: How Do You Say French Toast In Spanish (Mexico)? How To Say 'French Toast' In Spanish

3. The history and origin of Romex Wire (don"t pick this, so boring)

WARNING: You are responsible for your own safety and that of those around you. This article is my opinion. I am not a licensed electrician. You should consult with your municipal building department to see if you are allowed to work with electricity without a license. bsci-ch.org cannot be held liable for injuries or damages.