Studio Matrx Monthly · Volume 1 · Issue 2 · July 2026
Amogh N P
 In loving memory of Amogh N P — Architect · Designer · Visionary 
← The Electrical Knowledge Hub

Speaker Wire Gauge Calculator

Get the right speaker cable size so a long run doesn’t lose sound. Pick the speaker impedance and the run length, and see the recommended gauge in sq mm (and AWG), with the cable resistance and power loss. Ideal for home theatre and multiroom audio runs.

10 m

The distance from the amplifier to the speaker (the tool accounts for the return conductor).

The rule of thumb: keep the round-trip cable resistance under about 5% of the speaker impedance so power loss stays negligible. Lower impedance and longer runs need a thicker cable.

Recommended gauge
0.0 mm²

17 AWG · for a 10 m run to a 8Ω speaker.

Cable resistance (round trip)
0.00 Ω
4.3% of speaker impedance
Power loss in cable
0.00 dB
negligible below ~0.5 dB

Going one size up is cheap insurance on long or in-wall runs you can’t easily change later. Buy quality copper speaker cable and keep it separated from mains wiring to avoid hum.

A planning guide, not a spec. This uses copper resistivity and the common 5%-of-impedance rule for a two-conductor run; real cable, connectors and speaker loads vary. For long in-wall runs, err thicker. AWG values are the nearest common equivalent. Have the low-voltage/AV cabling installed by a professional.