Electrical Wiring in the Home/comparing wires


QUESTION: Hello Greg,

I'm comparing two extension cords for 120v and 15amp or less, which of these two wires is thicker (less resistance)?

a wire composed of three separate gauge 14 cables (includes ground)


a gauge 10 wire with ground?

My doubt comes from not knowing how thick are the cables that compose the gauge 10 wire

Thanks, appreciated



ANSWER: If you took three 14 awg wires and connected them together at each end you create about an 8 awg, in affect.

The actual sizes are:

14 awg = 0.064084 inches

10 awg = 0.10189 inches

You cannot simply add up two 14 awg in inches to come up with the correct figure.

So, two 14 awg DOES NOT equal (0.064084 + 0.064084)  0.128168 inches

Hope that helps.

[an error occurred while processing this directive]---------- FOLLOW-UP ----------

QUESTION: Dear Greg,

Thank you for your quick response. If I'm understanding your explanation right, the cable composed of three 14 awg wires would be aproximately like an 8 awg wire,and therefore it's thicker than the 10 awg cable... Did I get the idea?

Thank you in advance,


I am not talking about thickness.

In the electrical world we talk about resistance, impedance and ampacity.

A rope is thicker, but has a really high resistance so we do not speak of "thickness".

So, if all three wires are 14 awg and tied properly together they would look like and act like an 8 awg wire to the electrons.  
About Electrical Wiring in the Home
This site answers questions related to home electrical wiring, home wiring, general electrical help,and other electrical questions related to aleternating current (AC). You can find help on the National Electical Code, home electrical issues, wiring electrical outlets, installing lighting, electrical grounding, and general electrical help for do-it-yourself projects not require an electrician. If you do not see your home electrical wiring question answered in this area then please ask your electrical wiring question here

Electrical Wiring in the Home

All Answers

Answers by Expert:

Ask Experts


Greg Hughes


Troubleshooting electrical including appliances and HVAC.


34 years of experience.

Both college and tech schools in this field.

©2017 About.com. All rights reserved.

[an error occurred while processing this directive]