Wire Gauge (AWG) Calculator

Lookup AWG, convert diameter/area, estimate resistance per length, and size wire using current + run length + allowed voltage drop. Runs locally in your browser.

How to Use

  1. Pick a mode (Sizing, Convert, or Table).
  2. Select material (Copper/Aluminum) and units.
  3. Enter your values; results update instantly.
  4. Use “Share Link” (right rail) to generate a URL that restores this tool state.

Notes: “Sizing” is an engineering estimate based on resistance/voltage-drop math and reference tables. Always verify with local electrical code and real-world conditions.

AWG Lab View
Fast lookup + conversions + sizing helper (no uploads).
AWG
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Diameter
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Area
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R / length
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Status: —
Inputs & Settings
Sizing uses round-trip length (out + back) unless you switch to one-way.
Tip: Use Sizing for wiring runs; Convert for measured wire; Resistance for quick math.
Material affects resistance (and thus voltage drop).
Examples: 5V, 12V/14.4V, 48V, 120V, 230V
DC/AC sizing depends on insulation, bundling, ambient temp, and code. This tool focuses on drop math.
Use one-way distance; tool can apply round-trip automatically.
Common targets: 3% (branch), 5% (total) — verify your standards.
Show Work (step-by-step)
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Work is shown in base units for clarity. Sizing mode uses voltage-drop math: Vdrop = I × R(total).

Reference & Formulas

  • Voltage drop: Vdrop = I × R(total)
  • Drop percent: % = (Vdrop / Vsystem) × 100
  • Power loss: Ploss = I² × R(total)
  • Area: A = π × (d/2)² (when converting from diameter)

Important: Ampacity depends on insulation rating, bundling, ambient temperature, and code. This tool is primarily a voltage-drop + resistance helper.

FAQ

Is wire sizing the same for DC and AC?

The voltage-drop math is the same conceptually, but real-world limits (ampacity, insulation, code rules, temperature rise) may differ by application.

Why does “round-trip length” matter?

In most DC circuits, current goes out and returns on a second conductor, so resistance is based on the total conductor length.

What about stranded vs solid wire?

The AWG diameter/area standard is based on conductor cross-sectional area. Strand count can affect flexibility and packing, but DC resistance is mostly driven by total copper/aluminum area.

Do temperature changes affect resistance?

Yes. Resistance rises with temperature. This tool uses a reference baseline; you can include a temperature correction in the next file (JS) if you want it.

Tool Info

Last updated:

Updates may include dataset refinements, edge-case handling (1/0–4/0), and UI improvements.