Wire Gauge Chart: AWG Diameter in Inches, mm, and AreaAmerican Wire Gauge reference from 0000 (4/0) to 40 AWG

Use this wire gauge chart to look up American Wire Gauge (AWG) diameter in decimal inches and millimeters, plus calculated cross-sectional area. The table is a diameter and area reference only. It does not provide universal ampacity or current capacity because real wire selection depends on conductor material, insulation, temperature, installation method, bundling, local electrical code, and manufacturer specifications.

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AWG Diameter Lookup

Find AWG 0000 (4/0) through 40 with diameter in inches and millimeters.

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Area Calculation

Compare calculated cross-sectional area in mm² using the displayed diameter formula.

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Safety Caveats

Use the chart for geometry reference only, not as an ampacity or code-compliance calculator.

Answer first: AWG wire gauge to diameter

AWG wire gauge numbers define a geometric diameter series. AWG 12 is about 0.08081 in / 2.053 mm, AWG 14 is about 0.06408 in / 1.628 mm, and AWG 0000 (4/0) is about 0.46000 in / 11.684 mm.

Smaller AWG numbers mean larger wire diameter. Diameter and area do not by themselves determine safe current capacity.

Search, Print & Export

Showing 44 AWG rows from 0000 (4/0) through 40. On small screens, swipe the table horizontally to see all columns.

AWG wire gauge diameter chart

Search AWG 0000 (4/0) through 40. Diameter is generated from the AWG formula, converted to millimeters, and area is calculated from nominal round diameter.

AWG gauge	n ↑	Diameter inch	Diameter mm	Area mm²	Area kcmil	Notes / caveats
0000 (4/0)	-3	0.46000	11.684 mm	107.219 mm²	211.600 kcmil	Large AWG size; verify conductor material, stranding, insulation, and code before selecting cable.
000 (3/0)	-2	0.40964	10.405 mm	85.029 mm²	167.806 kcmil	Large AWG size; verify conductor material, stranding, insulation, and code before selecting cable.
00 (2/0)	-1	0.36480	9.266 mm	67.431 mm²	133.077 kcmil	Large AWG size; verify conductor material, stranding, insulation, and code before selecting cable.
0 (1/0)	0	0.32486	8.251 mm	53.475 mm²	105.535 kcmil	Large AWG size; verify conductor material, stranding, insulation, and code before selecting cable.
1	1	0.28930	7.348 mm	42.408 mm²	83.693 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
2	2	0.25763	6.544 mm	33.631 mm²	66.371 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
3	3	0.22942	5.827 mm	26.670 mm²	52.635 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
4	4	0.20431	5.189 mm	21.151 mm²	41.741 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
5	5	0.18194	4.621 mm	16.773 mm²	33.102 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
6	6	0.16202	4.115 mm	13.302 mm²	26.251 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
7	7	0.14429	3.665 mm	10.549 mm²	20.818 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
8	8	0.12849	3.264 mm	8.366 mm²	16.510 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
9	9	0.11442	2.906 mm	6.634 mm²	13.093 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
10	10	0.10190	2.588 mm	5.261 mm²	10.383 kcmil	Diameter/area reference only; do not infer ampacity without installation details.
11	11	0.09074	2.305 mm	4.172 mm²	8.234 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
12	12	0.08081	2.053 mm	3.309 mm²	6.530 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
13	13	0.07196	1.828 mm	2.624 mm²	5.178 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
14	14	0.06408	1.628 mm	2.081 mm²	4.107 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
15	15	0.05707	1.450 mm	1.650 mm²	3.257 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
16	16	0.05082	1.291 mm	1.309 mm²	2.583 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
17	17	0.04526	1.150 mm	1.038 mm²	2.048 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
18	18	0.04030	1.024 mm	0.823 mm²	1.624 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
19	19	0.03589	0.912 mm	0.653 mm²	1.288 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
20	20	0.03196	0.812 mm	0.518 mm²	1.022 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
21	21	0.02846	0.723 mm	0.410 mm²	0.810 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
22	22	0.02535	0.644 mm	0.326 mm²	0.642 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
23	23	0.02257	0.573 mm	0.258 mm²	0.509 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
24	24	0.02010	0.511 mm	0.205 mm²	0.404 kcmil	Common small-wire reference; actual conductor may be solid or stranded.
25	25	0.01790	0.455 mm	0.162 mm²	0.320 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
26	26	0.01594	0.405 mm	0.129 mm²	0.254 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
27	27	0.01420	0.361 mm	0.102 mm²	0.202 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
28	28	0.01264	0.321 mm	0.081 mm²	0.160 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
29	29	0.01126	0.286 mm	0.064 mm²	0.127 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
30	30	0.01003	0.255 mm	0.051 mm²	0.101 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
31	31	0.00893	0.227 mm	0.040 mm²	0.080 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
32	32	0.00795	0.202 mm	0.032 mm²	0.063 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
33	33	0.00708	0.180 mm	0.025 mm²	0.050 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
34	34	0.00630	0.160 mm	0.020 mm²	0.040 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
35	35	0.00561	0.143 mm	0.016 mm²	0.032 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
36	36	0.00500	0.127 mm	0.013 mm²	0.025 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
37	37	0.00445	0.113 mm	0.010 mm²	0.020 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
38	38	0.00397	0.101 mm	0.008 mm²	0.016 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
39	39	0.00353	0.090 mm	0.006 mm²	0.012 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.
40	40	0.00314	0.080 mm	0.005 mm²	0.010 kcmil	Fine-wire reference; verify manufacturer tolerance and strand construction.

AWG formula:d_in = 0.005 × 92^((36 - n) / 39)

Metric:d_mm = d_in × 25.4

Last reviewed:2026-07-06

Diameter and area do not determine safe current capacity by themselves. Do not use this chart as a substitute for electrical code or manufacturer ampacity data.

AWG diameter formula and rounding

Diameter formula: d_in = 0.005 × 92^((36 - n) / 39).
Metric conversion: d_mm = d_in × 25.4.
Area formula: area_mm² = π × (d_mm / 2)^2.
Area kcmil: area_kcmil = (diameter_inch × 1000)^2 / 1000.
Gauge index: n = -3 represents 0000 (4/0), n = 0 represents 0 (1/0), and n = 40 represents 40 AWG.
Rounding: Diameter inches display to 5 decimals; millimeters, area mm², and kcmil display to 3 decimals where useful for table scanning.

Important safety note

This wire gauge chart is a diameter and calculated-area reference only. It is not a universal ampacity or current-capacity chart. Safe wire selection depends on conductor material, insulation rating, temperature, installation method, raceway or free-air conditions, bundling, voltage drop, local electrical code, and manufacturer specifications. Always verify final wire selection with the applicable code, standard, and qualified engineering or electrical authority.

Common AWG wire gauge examples

Use these examples for quick lookup, then verify conductor construction and electrical requirements before using a wire in a real installation.

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12 AWG diameter

12 AWG is about 0.08081 in / 2.053 mm, with calculated area about 3.309 mm².

Geometry reference only

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14 AWG diameter

14 AWG is about 0.06408 in / 1.628 mm, with calculated area about 2.081 mm².

Geometry reference only

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18 AWG diameter

18 AWG is about 0.04030 in / 1.024 mm, with calculated area about 0.823 mm².

Geometry reference only

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4/0 AWG diameter

0000 (4/0) AWG is about 0.46000 in / 11.684 mm, with calculated area about 107.219 mm².

Geometry reference only

How to use this wire gauge chart

Find the AWG number from your drawing, label, or datasheet.
Read the nominal diameter in inches and millimeters.
Use the calculated area only as a geometry reference.
Confirm whether the conductor is solid or stranded.
For current, voltage drop, or safety decisions, check code and manufacturer data.

AWG vs SWG: do not mix gauge systems

AWG and SWG are different gauge systems. This chart uses AWG values only. Do not treat AWG and SWG gauge numbers as interchangeable.

Data and calculation assumptions

Gauge system: AWG / American Wire Gauge.
Diameter source: Diameter values are generated from the standard AWG geometric formula and converted with 1 inch = 25.4 mm.
Reference scope: nominal solid round diameter and geometry reference only.
Caveat: Diameter and calculated area are geometry references only. They do not determine safe ampacity, current capacity, or code compliance by themselves.
Last reviewed: 2026-07-06.

Wire Gauge Chart FAQ

What is a wire gauge chart?

A wire gauge chart maps gauge numbers to nominal wire diameter and calculated cross-sectional area. This page focuses on American Wire Gauge (AWG) values from 0000 (4/0) through 40 AWG.

How do you convert AWG to millimeters?

Use the AWG diameter formula to get diameter in inches, then multiply by 25.4 to convert inches to millimeters. For example, 12 AWG is about 0.08081 inch, which is about 2.053 mm.

What is 12 AWG in mm?

12 AWG is about 2.053 mm in nominal diameter, with calculated cross-sectional area of about 3.309 mm². This is a diameter and area reference, not a universal current rating.

What is 14 AWG in mm?

14 AWG is about 1.628 mm in nominal diameter, with calculated cross-sectional area of about 2.081 mm². Always verify conductor material, insulation, and code requirements before selecting wire.

Does a smaller AWG number mean a larger wire?

Yes. In the AWG system, smaller gauge numbers mean larger wire diameter. Sizes with zeros, such as 0, 00, 000, and 0000 (4/0), are larger than 1 AWG.

Is AWG the same as SWG?

No. AWG and SWG are different gauge systems. The same gauge number can mean a different diameter, so AWG and SWG values should not be mixed or treated as interchangeable.

Can I use this chart to choose wire ampacity?

No. This chart does not provide universal ampacity or current capacity. Ampacity depends on material, insulation, temperature, installation method, bundling, local electrical code, and manufacturer specifications.

Why does the chart include cross-sectional area?

Cross-sectional area helps compare conductor geometry, and it is calculated from the nominal diameter. It does not by itself determine safe current capacity, voltage drop, or code compliance.

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