Question 1

What does AWG stand for?

Accepted Answer

AWG stands for American Wire Gauge. It's a standardized wire sizing system used primarily in North America. The gauge number indicates the number of drawing operations used to produce a given wire diameter -- historically, higher numbers meant more draws and thinner wire.

Question 2

Why do smaller AWG numbers mean thicker wire?

Accepted Answer

The AWG system is based on the number of times wire was drawn through progressively smaller dies during manufacturing. More drawing steps (higher gauge number) produced thinner wire. AWG 0 (1/0) is about 8.25 mm diameter, while AWG 40 is only 0.08 mm.

Question 3

What AWG do I need for a 20-amp circuit?

Accepted Answer

For a standard 20-amp residential circuit, the National Electrical Code requires a minimum of 12 AWG copper wire. For a 15-amp circuit, 14 AWG is the minimum. Always follow your local electrical code, which may have stricter requirements.

Question 4

How does AWG relate to metric wire sizes?

Accepted Answer

Metric wire is specified by cross-sectional area in mm2, not by gauge number. There's no exact one-to-one match. For example, 12 AWG (3.31 mm2) is close to the metric 3.5 mm2 size, and 14 AWG (2.08 mm2) is close to the metric 2.5 mm2 size.

AWG	Diameter (mm)	Area (mm2)	Resistance (ohm/1000ft)	Typical Use
4	5.189	21.15	0.249	Service entrance
8	3.264	8.37	0.628	Range/dryer circuits
10	2.588	5.26	0.999	30A circuits
12	2.053	3.31	1.588	20A household circuits
14	1.628	2.08	2.525	15A household circuits
16	1.291	1.31	4.016	Extension cords
18	1.024	0.82	6.385	Lamp cords, low-voltage
22	0.644	0.33	16.14	Electronics, data

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