Speaker and RF cable calculator

Calculate RF insertion loss and a separate resistive speaker-cable loss from your cable datasheet values.

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Cable length (metres, one way)

RF attenuation at operating frequency (dB / 100 m)

More inputs and assumptions

RF connector and accessory loss (dB)

Speaker conductor resistance (ohms / 100 m)

Speaker load resistance (ohms)

Answer

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Calculate RF insertion loss and a separate resistive speaker-cable loss from your cable datasheet values.

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Formula and assumptions

Enter RF attenuation for the actual frequency and conditions; no cable model is assumed. RF loss is length times specified attenuation plus accessory loss. Speaker loss uses two conductors and a purely resistive load with zero amplifier output resistance. Real loudspeaker impedance varies with frequency. The RF and speaker outputs are separate models, not an assertion that one cable suits both uses.

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Updated 2026-09-29

Using Speaker and RF cable calculator

Calculate RF insertion loss and a separate resistive speaker-cable loss from your cable datasheet values.

Next: Ohm's law calculator

Next: Voltage drop calculator

A worked example

For cable length (metres, one way) = 20, rf attenuation at operating frequency (db / 100 m) = 10, rf connector and accessory loss (db) = 1, speaker conductor resistance (ohms / 100 m) = 1, speaker load resistance (ohms) = 8, rf total loss (db) = 3.

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Example results for cable length (metres, one way)

These examples use RF attenuation at operating frequency (dB / 100 m): 10; RF connector and accessory loss (dB): 1; Speaker conductor resistance (ohms / 100 m): 1; Speaker load resistance (ohms): 8. They are reference calculations, not recommended settings.

Cable length (metres, one way)	RF total loss (dB)
10	2
20	3
40	5

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