Speaker Impedance Matching Calculator

Work out speaker impedance matching instantly with clear inputs, formula shown and shareable results.

About Speaker Impedance Matching Calculator

Parallel speakers divide the impedance by their number, series wiring multiplies it, and series-parallel pairs give twice the driver impedance divided by the number of pairs. Amplifier output roughly doubles as impedance halves, which is why wiring four 8 ohm speakers in parallel presents a 2 ohm load that many amplifiers cannot survive.

Formulas

Parallel load

total = impedance / number of speakers

Series load

total = impedance x number of speakers

Worked example

With the default values below, Speaker Impedance Matching Calculator returns Total load impedance of 2.000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Number of speakersaccepts 1–16: 4
Impedance of each speakerminimum 0.1 ohm: 8 ohm
Wiringone of Parallel, Series, Series-parallel pairs: Parallel
Amplifier power at 8 ohmsminimum 1 W: 100 W

Results

Total load impedance: 2.000 ohm
Power the amplifier will deliver: 400.00 W
Power per speaker: 100.00 W
Load assessment: Only for amplifiers rated to 2 ohms

Step by step

1Values used
2Parallel load
3Series load
4Total load impedance= 2.000 ohm
5Power the amplifier will deliver= 400.00 W
6Power per speaker= 100.00 W
7Load assessment= Only for amplifiers rated to 2 ohms

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Speaker Impedance Matching figure worked out?

total = impedance / number of speakers. Parallel speakers divide the impedance by their number, series wiring multiplies it, and series-parallel pairs give twice the driver impedance divided by the number of pairs.

Why does this matter?

Amplifier output roughly doubles as impedance halves, which is why wiring four 8 ohm speakers in parallel presents a 2 ohm load that many amplifiers cannot survive.

What do I need to enter?

Enter number of speakers, impedance of each speaker, wiring, amplifier power at 8 ohms. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.