Speaker wire resistance calculator

This function calculates the electrical resistance of a speaker wire. Specialist knowledge is not required. Just enter the simple length of the line in meters and the cross section of the wire in square millimeters. Copper wire is assumed to be the material. The result is the total ohmic resistance of the two-pole line.

You can find cable calculators for other materials or single wires here.

Things to know about speaker cables

In many forums there are endless and equally useless discussions about the loss of power and volume on speaker lines. Whether you can afford to lose 10% or more with a 200 watt power amplifier only plays a role at boozy parties where, with increasing alcohol consumption, the volume plays a greater role than the quality of the transmission.

For the audiophile music lover, however, the quality of the transmission is paramount, and this decreases with increasing line resistance. Among other things, the speaker's natural vibrations, caused by resonance and self-induction, are kept in check by the amplifier. However, this only works with a low-impedance coupling of the loudspeaker to the amplifier.

With good, powerful speakers with several meters of connection cable, even inexperienced listeners can perceive the rough sound and grumpy bass of 0.75mm₂ cable compared to the smooth sound of 4mm₂ cross-section. In the manual for its 5SM S2 boxes, Bowers + Wilkins recommends a line resistance of less than 0.1 ohms. This can also apply to others as a guideline.