Wire Gauge Chart (AWG)
American Wire Gauge sizes with approximate solid-copper diameter. Use this table to read a stamp or convert a label — not to design a house circuit. Common branch questions live on the ampacity chart and the AWG tool.
Reference only. Confirm AWG on the product, temperature rating, and local code. Not a substitute for a licensed electrician. Disclaimer
| AWG | Diameter (in) | Diameter (mm) | Common association (shop) |
|---|---|---|---|
| 4/0 AWG | 0.4600 | 11.68 | Service entrance / large feeder conductor |
| 3/0 AWG | 0.4096 | 10.40 | Service entrance / large feeder |
| 2/0 AWG | 0.3648 | 9.27 | Service entrance / large feeder |
| 1/0 AWG | 0.3249 | 8.25 | Sub-panel feeder / large load |
| 1 AWG | 0.2893 | 7.35 | Sub-panel feeder / large load (conditions apply) |
| 2 AWG | 0.2576 | 6.54 | Large feeder (conditions apply) |
| 3 AWG | 0.2294 | 5.83 | Large feeder (conditions apply) |
| 4 AWG | 0.2043 | 5.19 | Feeder / high-load circuit (conditions apply) |
| 6 AWG | 0.1620 | 4.12 | Higher capacity runs (conditions apply) |
| 8 AWG | 0.1285 | 3.26 | Larger feeders / higher load (conditions apply) |
| 10 AWG | 0.1019 | 2.59 | Often associated with 30A copper (conditions apply) |
| 12 AWG | 0.0808 | 2.05 | Often associated with 20A copper branch (conditions apply) |
| 14 AWG | 0.0641 | 1.63 | Often associated with 15A copper branch (conditions apply) |
| 16 AWG | 0.0508 | 1.29 | Light duty extension / low current — no NEC ampacity rating |
| 18 AWG | 0.0403 | 1.02 | Low-current / lamp cord class — no NEC ampacity rating |
| 20 AWG | 0.0320 | 0.81 | Signal / electronics wire — no NEC ampacity rating |
Sample-length copper (12 AWG)
Not whole-house cable. One short-length 12 AWG option for shop experiments — confirm AWG on the listing. Permanent wiring still needs code and a qualified electrician.
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How to read this chart
Start with the AWG number on the insulation or the plan. Diameter columns are approximate solid copper — stranded cord and thick insulation look larger in the hand. The “common association” column is a short shop hint only (for example 12 AWG with 20A copper branch questions); temperature, insulation type, and code still win.
For a scene such as “what gauge for 20 amp?”, open the 20 amp decide page or the AWG tool. Temporary cord runs are a different job — use the extension cord gauge helper.
FAQ
What is AWG?
American Wire Gauge. Larger numbers are thinner wire (18 AWG is thinner than 12 AWG). Diameter columns on this chart are approximate solid-copper values for workshop comparison.
Is this chart a substitute for electrical code?
No. It is an educational size reference for home-shop questions. Branch-circuit design, temperature ratings, conduit fill, and terminations require the local electrical code and a qualified electrician when the job is not a temporary cord-style question.
How do I use this chart with the AWG tool?
Scan the AWG column for the stamp on the wire or the size in your question, then open the AWG / ampacity tool to walk a scene (15A / 20A / 30A-class) or pick a gauge with a short condition note.
Why do some AWG sizes look thicker than I expected?
This table shows approximate bare conductor diameter, not insulation outer diameter. Jacket type and stranding change the overall cord size.
Sources
AWG diameters follow common published copper wire tables used in workshop and education references. Ampacity associations on this site are simplified and are not a code table.
See the site disclaimer for limits of use.