AWG wire gauge calculator
Turn an AWG size into solid-copper diameter, cross-section and DC resistance: AWG 10 is about 2.59 mm across with 5.26 mm² of copper. Resistance comes per metre, per kilometre and per thousand feet at 20 °C. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- American Wire Gauge
- 10
- Awg
- 10
- Awg label
- 10
- Diameter in
- 0.1018971153
- Diameter mm
- 2.588186728
American Wire Gauge (AWG) is the standard logarithmic scale used across North America and much of the electronics industry to size solid round copper conductors. Larger gauge numbers mean thinner wire: AWG 24 is fine instrument wire, AWG 12 is common branch-circuit copper, and 4/0 (also written 0000) is heavy service entrance cable. Given a single AWG size, this calculator returns solid-conductor diameter in inches and millimetres, cross-sectional area in square millimetres, square metres, and circular mils, plus DC resistance per metre, per kilometre, and per thousand feet for annealed copper at twenty degrees Celsius. The diameter follows the ASTM B258 closed form, area is the geometric circle of that diameter, and resistance is resistivity over area with the IEC annealed-copper baseline. Out-of-range gauges are rejected with a clear validation error instead of inventing values.
How AWG diameter, area, and resistance are computed
The American Wire Gauge system is defined so that diameter forms a geometric series: each step of three gauges multiplies diameter by a factor of two, and the full span from AWG 36 to AWG 0000 is fixed by ASTM B258.
The closed-form diameter in inches is d equals zero point zero zero five times ninety-two raised to the power of thirty-six minus n over thirty-nine, where n is the integer gauge with n equals negative three for 0000 (4/0), negative two for 000 (3/0), negative one for 00 (2/0), zero for 0 (1/0), and positive integers one through forty for the remaining sizes. Convert inches to millimetres by multiplying by twenty-five point four.
Cross-sectional area assumes a perfect solid circular cross-section: A equals pi times radius squared, reported in square millimetres, square metres, and circular mils where circular mils equal the square of the diameter expressed in thousandths of an inch. DC resistance for annealed copper at twenty degrees Celsius uses resistivity rho equals one point seven two four one times ten to the minus eight ohm-metres, so R per metre equals rho divided by area in square metres.
From that baseline the response also scales to ohms per kilometre and ohms per thousand feet using exact length conversion factors. Stranded constructions, temperature coefficients, aluminum, and insulation outer diameter are intentionally out of scope so this landing stays a pure solid-AWG geometry and baseline copper resistance oracle.
Where AWG wire calculators show up in real work
Electronics technicians and hobbyists constantly convert a gauge stamped on magnet wire or hook-up wire into diameter and ohms per metre when estimating voltage drop on sensor runs or choosing fuse wire thickness. Electrical designers size branch circuits, feeders, and control cabling against ampacity tables that are indexed by AWG, then still need geometric area and DC resistance for heat, IR drop, and cable mass estimates before ordering reels.
PCB and harness engineers map schematic net current to recommended AWG for chassis wiring and need a single trusted oracle that matches datasheet tables within floating-point noise. Curriculum authors teaching the logarithmic gauge scale want diameter, circular mils, and resistance side by side so students can verify the factor-of-two diameter rule every three gauges. Procurement and ERP systems enrich part numbers that only list AWG with SI cross-sections for regional compliance labels.
If you later need ampacity derating, voltage drop over a stated length and load, stranded equivalent gauges, or aluminum resistivity at elevated temperature, treat those as separate search intents and landings rather than overloading this solid AWG geometry page.
What you can do with it
Bench and lab wire identification
Convert a stamped AWG size into diameter, mm², and ohms per metre so technicians can match scrap wire to a BOM without flipping paper tables.
Harness and control-cable design
Enrich schematic wire gauges with solid copper area and baseline DC resistance for IR-drop and mass estimates before ampacity tables.
BOM and ERP enrichment
Batch-map AWG part attributes to SI cross-sections and Ω/m so regional labels and costing sheets share one deterministic source.
FAQ
What AWG range does this calculator support?
Solid AWG from −3 (0000 / 4/0) through 40 inclusive. Labels such as 00, 000, 0000, 2/0, 3/0, and 4/0 are accepted.
How is diameter calculated?
Millimetres follow by multiplying by 25.4. This matches standard solid-wire tables within floating-point precision.
Is resistance for copper or aluminum?
Annealed copper only at 20 °C, using resistivity 1.7241×10⁻⁸ Ω·m. Aluminum, tinning, and temperature coefficients are out of scope for this landing.
Does it handle stranded wire?
No. Geometry assumes a solid circular conductor of the nominal AWG diameter. Stranded constructions have different effective diameters and fill factors and belong on a separate tool.
What does it cost?
The browser tool is free and runs locally.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/elec/awg-wire \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"awg":"10"}'const res = await fetch("https://api.kit.forhosting.com/elec/awg-wire", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"awg": "10"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/elec/awg-wire",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"awg": "10"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/elec/awg-wire", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"awg":"10"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"awg":"10"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/elec/awg-wire", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"awg": "10"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "elec.awg_wire",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
How AWG diameter, area, and resistance are computed
The entire pipeline is deterministic floating-point arithmetic: no random seeds, no wall-clock timestamps, no network calls, and no model drift, so identical gauges always produce identical JSON.
What you send and what you get back
Values may be integers from negative three through forty, or common labels such as ten, twenty-two, zero, double-zero, triple-zero, quadruple-zero, and the slash forms four-slash-zero through one-slash-zero. Provide exactly one of those field names; conflicting simultaneous keys fail validation. Classic checks include AWG ten near two point five nine millimetres with about five point two six square millimetres of copper, AWG twelve near two point zero five millimetres, and 4/0 as the largest supported power size. Send a single AWG field under awg, or the aliases gauge, wire_gauge, or n. Missing fields, non-numeric garbage, fractional gauges, and any size outside the supported solid range fail with invalid_input and are not charged. On success the response echoes the integer awg, a human-readable awg_label, diameter_in, diameter_mm, and diameter_m, area_mm2, area_m2, and area_circular_mils, resistance_ohm_per_m, resistance_ohm_per_km, and resistance_ohm_per_kft, plus material annealed_copper, temperature_c twenty, the resistivity constant, unit labels, method astm_b258_awg, and a short formula string. Pricing for successful API calls is the published base of $0.002 per item; validation failures do not consume prepaid balance.
Where AWG wire calculators show up in real work
Because this capability is a pure parse engine, API pricing is the published base of $0.002 per successful item and failed validation does not consume balance.