What cable gauge do I need for speaker cables?

For runs under 5m at 8 ohms: 16 AWG. For 5-15m: 14 AWG. For 15-30m: 12 AWG. For 4-ohm loads, go one gauge thicker. These guidelines keep power loss under 5%. For professional installations, 2% or less loss is preferred.

AWG (American Wire Gauge) is a standardised system for wire sizes. Lower numbers mean thicker wire. Each 3-gauge reduction doubles the cross-sectional area and halves the resistance. Common speaker cable gauges are 12-18 AWG.

Can I use thicker cable than recommended?

Yes, thicker cable always reduces loss. The only downsides are cost, weight and flexibility. There is no electrical downside to using thicker cable. However, beyond a certain point the improvement is negligible.

Does cable quality matter beyond gauge?

For speaker cables, gauge (and therefore resistance) is by far the most important factor. The conductor material (oxygen-free copper vs standard copper) makes a negligible difference at audio frequencies. Good insulation and durable connectors are more important than exotic materials.

AudioCalcs

Cable Gauge Calculator — AWG for Speaker Cables

Calculate required cable gauge (AWG) for speaker cables based on length and impedance.

Cable Length (one way)

Length measurement

Speaker Impedance

Electrical impedance in ohms

Max Acceptable Loss

Enter the max acceptable loss

How We Calculate This

Maximum Resistance

Max R = (Max Loss % / 100) × Speaker Impedance

Cable Resistance

R = Resistance per metre × Length × 2

Multiply by 2 for the round trip (positive and negative conductors).

Power Loss

Loss (%) = R_cable / (R_speaker + R_cable) × 100

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard formulas. Always verify results for critical applications.