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⚡ Wire Gauge (AWG) Calculator

Wire Gauge (AWG) Calculator

Inputs

AWG

Results

Enter a value and press Calculate

Calculator Description

AWG (American Wire Gauge) is the wire diameter standard used in North America. Lower gauge numbers mean thicker wire with higher current capacity. This calculator looks up wire dimensions, cross-sectional area, and resistance from an AWG gauge number.

What this calculator finds

Enter an AWG gauge number (0000–50) to see the wire's diameter (mm, inch), cross-sectional area (mm², cmil), DC resistance per 1000ft (Ω), and ampacity.

Why it matters

  • Proper wire gauge selection is essential for preventing overheating and ensuring safety in wiring design
  • Electrical/electronic equipment design requires considering both current capacity and voltage drop
  • Compliance with minimum wire gauge requirements in electrical codes like UL and NEC is mandatory

Formula

AWG Diameter Formula

For AWG gauge number n, the wire diameter is calculated by the following formula. Each increase in gauge number reduces the diameter by approximately 12.2%.

d(n)=0.127 mm×92(36−n)/39d(n) = 0.127\,\text{mm} \times 92^{(36-n)/39}
d(n)=0.005 inch×92(36−n)/39d(n) = 0.005\,\text{inch} \times 92^{(36-n)/39}
  • d(n) — Wire diameter at gauge number n [mm or inch]
  • n — AWG gauge number (0000=−3, 00=−2, 0=−1, 1–50)
  • 92 — Diameter ratio base in the 92^((36-n)/39) formula

Cross-section and resistance relationships

A=πd24A = \dfrac{\pi d^{2}}{4}
R=ρLAR = \dfrac{\rho L}{A}
  • A — Cross-sectional area [mm², cmil]
  • R — Resistance [Ω]
  • ρ — Electrical resistivity [Ω·m] (copper: 1.68×10⁻⁸)
  • L — Wire length [m]

Common AWG sizes

  • 14 AWG: 1.628 mm, 15A (residential wiring)
  • 12 AWG: 2.053 mm, 20A (kitchen/bathroom wiring)
  • 10 AWG: 2.588 mm, 30A (AC/induction cooktop)
  • 8 AWG: 3.264 mm, 50A (electric oven)
  • 6 AWG: 4.115 mm, 65A (sub-panel)

Useful Tips

Practical tips

  • Check voltage drop as well as ampacity when selecting wire gauge
  • Voltage drop (recommended within 3%) can become a limiting factor in long-distance wiring
  • Copper wire ampacity varies depending on installation environment (enclosed duct, open air, etc.)

Limitations & cautions

  • This calculator is for copper (Cu) wire; aluminum (Al) has about 1.6× higher resistivity
  • Ampacity values are based on NEC Table 310.16 and require correction for ambient temperature and installation conditions
  • Stranded wire has different skin effect resistance at high frequencies due to larger surface area