Reference Data

AWG Wire Gauge Chart

// COMPLETE AMERICAN WIRE GAUGE REFERENCE TABLE WITH SPECIFICATIONS //

SYSTEM_INFO

UNDERSTANDING AWG WIRE GAUGE

The American Wire Gauge (AWG) system uses an inverse numbering system: smaller gauge numbers indicate larger wire diameters and higher current capacity. AWG 0000 (4/0) is the largest common wire gauge, while AWG 20 is suitable for low-current applications.

AWG_DATA_TABLE
AWGDIAMETERCROSS-SECTIONRESISTANCE (Ω/1000ft)AMPACITY - COPPERAMPACITY - ALUMINUM
mminchmm²kcmilCuAl60°C75°C90°C60°C75°C90°C
200.8120.03200.521.0210.15016.700111115---
181.0240.04030.821.626.39010.500141418---
161.2910.05081.312.584.0206.600181824---
141.6280.06412.084.112.5304.160252535202025
122.0530.08083.316.531.5902.610303540252530
102.5880.10195.2610.381.0001.640405055304045
83.2640.12858.3716.510.6281.030607080455565
64.1150.162013.3026.240.3950.6488095105607585
45.1890.204321.1541.740.2490.40810512514080100110
35.8270.229426.6752.620.1970.32412014516595115130
26.5440.257633.6266.370.1560.256140170190110135150
17.3480.289342.4183.690.1240.203165195220130155175
1/08.2510.324953.49105.600.0980.161195230260150180205
2/09.2660.364867.43133.100.0780.128225265300175210235
3/010.4000.409685.01167.800.0620.101260310350200240275
4/011.6800.4600107.20211.600.0490.081300360405235280315
WIRE_DIAMETER

Wire Diameter

Wire diameter decreases as AWG gauge number increases. Each increase of 6 gauge numbers approximately doubles the wire diameter.

Key Points:

  • AWG 10 = 2.588mm
  • AWG 16 = 1.291mm
  • AWG 4 = 5.189mm
AMPACITY_RATINGS

Ampacity Ratings

Ampacity is the maximum current a conductor can carry continuously without exceeding its temperature rating. Values based on NEC Table 310.16.

Temperature Ratings:

  • 60°C - Standard thermoplastic (TW)
  • 75°C - Heat-resistant (THHN, THWN)
  • 90°C - High heat-resistant (XHHW)
UNDERSTANDING_AWG_SYSTEM

Understanding the American Wire Gauge System

The American Wire Gauge (AWG) system is the standardized wire gauge measurement system used predominantly in North America for measuring the diameter of round, solid, nonferrous, electrically conducting wire. Originally developed in 1857, the AWG system provides a consistent method for specifying wire sizes across the electrical industry, ensuring safety and compatibility in electrical installations.

Inverse Scale

Smaller numbers = larger wires

Logarithmic

Each 3 AWG = 2× area change

North American

Standard in USA & Canada

How AWG Sizing Works

The AWG system is based on the number of drawing operations required to produce a given wire diameter. Starting with a reference diameter, wire is drawn through progressively smaller dies until the desired size is achieved. This historical manufacturing process explains the inverse numbering system: more drawing operations produce thinner wire with higher gauge numbers.

4/0

Largest Common

11.68mm

10

General Purpose

2.59mm

14

Branch Circuits

1.63mm

20

Low Current

0.81mm

AWG_CONVERSION_FORMULAS

AWG to Metric Conversion Formulas

Converting between AWG and metric measurements requires understanding the mathematical relationships in the wire gauge system. The formulas below allow precise conversion between AWG gauge numbers and metric dimensions.

Diameter Formula

d(mm) = 0.127 × 92((36-AWG)/39)

This formula calculates wire diameter in millimeters from the AWG gauge number. The constants 36 and 39 define the gauge progression, while 0.127mm is the reference diameter for 36 AWG.

Cross-Sectional Area

A(mm²) = π × (d/2)² = 0.012668 × 92((36-AWG)/19.5)

Cross-sectional area determines current-carrying capacity. Each decrease of 3 AWG numbers approximately doubles the cross-sectional area.

Quick AWG to mm² Conversion

AWG4/02/01468101214
mm²107.267.442.421.213.38.375.263.312.08
Metric Equiv.120mm²70mm²50mm²25mm²16mm²10mm²6mm²4mm²2.5mm²
RELATED_TOOLS

Wire Sizing Calculators & Tools

Use our suite of electrical calculators to simplify wire sizing decisions. Each tool handles specific calculations automatically while following NEC guidelines.

Wire Gauge Calculator

Automatic wire size selection based on current and distance

Voltage Drop Calculator

Calculate voltage drop for any wire size and length

Ampacity Calculator

Determine ampacity with derating factors

Resistance Calculator

Calculate wire resistance for any gauge

QUICK_CALCULATOR

NEED TO CALCULATE WIRE SIZE?

Use our free wire gauge calculator to get instant recommendations based on your specific requirements.

USE WIRE CALCULATOR

What This AWG Chart Defines

American Wire Gauge is a standardized wire-diameter system used to compare conductor size, electrical resistance, and installation practicality across common copper and aluminum conductors. A wire harness is a routed bundle of conductors, terminals, coverings, and breakout points that keeps wiring organized inside equipment. Cable assembly refers to a finished cable product with insulation, optional shielding, and terminations selected for a known electrical and mechanical duty.

Comparison Table

Decision pointWhat the chart gives youWhat still needs engineering review
GaugeRelative diameter and areaConnector fit, bend radius, and strand class
ResistanceVoltage-drop starting pointRun length, phase, and allowable equipment drop
AmpacityBaseline current capacityTemperature rating, derating, and 125% continuous load checks
MaterialCopper versus aluminum trendTermination hardware, corrosion, and physical space

Frequently Asked Questions

Why is the AWG number smaller when the wire is larger?

The numbering system developed from historical drawing steps, so thicker conductors ended up with lower gauge numbers. Modern users mostly care about the result: lower AWG numbers mean lower resistance, more copper or aluminum, higher current capacity, and often less voltage drop over the same distance.

When does an AWG chart stop being enough?

An AWG chart stops being enough when the project has long runs, continuous loads, high ambient temperature, bundled conductors, motor starting current, or unusual terminals. In those cases the chart is still useful, but a calculator and code review determine whether the next larger conductor is justified.

A wire harness is what exactly in practical terms?

A wire harness is an organized wiring system that groups conductors, insulation supports, labels, terminals, seals, and breakout branches so power and signals can be routed repeatably. Harness work is not just about gauge; it also depends on routing, strain relief, connector orientation, abrasion protection, and repeatable termination quality.

Cable assembly refers to what, and how is it different?

Cable assembly refers to a finished cable product prepared for a specific use, often with connectors or sealed ends already installed. Compared with a larger wire harness, a cable assembly is usually narrower in scope and may be treated as one replaceable interconnect rather than an entire routed system.

Why do authoritative references belong on a calculator page?

Readers and search systems both benefit when technical definitions point to stable public entities. A citation to American Wire Gauge, wire harness terminology, crimping, or quality-system references helps clarify what the page is talking about and reduces ambiguity when similar terms are used across manufacturing, residential wiring, and automotive work.

Author and Sources

Reviewed by Hommer Zhao, General Manager and Wire Harness Engineer, affiliated with WIRINGO.