Thin or very long speaker wire wastes amplifier power as heat and can soften bass. Enter the length of the run and the speaker load to see how each common gauge (AWG) performs, and which is the thinnest gauge that keeps losses small.
The current flows to the speaker and back, so the wire resistance is the resistance per foot × 2 × the one-way length. The calculator uses standard copper resistance values at 20 °C (for example 2.525 Ω per 1,000 ft for 14 AWG). Power lost in the wire is wire resistance ÷ (wire resistance + speaker load), and the level drop at the speaker is 20 × log10(load ÷ (load + wire resistance)). A common rule of thumb keeps the wire resistance under 5% of the speaker load.
Copper-clad aluminum (CCA) wire has roughly 1.6 times the resistance of pure copper of the same gauge, so choose one size heavier if you use CCA. Lower impedances (2 Ω, 1 Ω) and long PA runs need much heavier wire. Read the full speaker wire gauge guide.
It depends on the length of the run and the speaker impedance. Short runs to 8 Ω speakers can use 16 AWG; long runs or 4 Ω and lower loads need 14, 12 or heavier. The calculator shows the thinnest gauge that stays under your loss limit.
Yes. A lower AWG number means a thicker wire with lower resistance: 12 AWG is thicker than 16 AWG.
Enter the one-way distance from amplifier to speaker. The calculator doubles it because current travels out and back.
It works, but it has about 1.6 times the resistance of copper of the same gauge, so use one gauge heavier than the calculator suggests for copper.
More free audio tools: Speaker impedance calculator · Amp wattage & SPL calculator · Speaker wire gauge calculator
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These calculators run entirely in your browser; nothing you type is sent or stored. Results are estimates based on standard formulas; always check your amplifier and speaker manuals.