Speakers in Parallel Calculator

The calculator below is useful in determining the total impedance of speakers in parallel. It also calculates how the power is shared between the speakers. If all the speakers have the same impedance, the calculation is relatively simple. 

Simple Impedance Calculation for Speakers in Parallel

If all the speakers in parallel have the same impedance, then the calculation is easy. Simply divide the impedance by the number of speakers in parallel.

Example 1: Four 8 ohm speakers in parallel: 8 divided by 4 = 2 ohms.

Example 2: Two 4 ohms speakers in parallel: 4 divided by 2 = 2 ohms.

Not so Simple Calculations for Speakers in Parallel

For calculations involving speakers in parallel with different impedance, the following formula is required (it can be used with speakers of similar impedances too).

\large{Imp_{Total}}=\frac{1}{\frac{1}{Imp_1}+\frac{1}{Imp_2}+\frac{1}{Imp_3}+ ...}

If you have a calculator with 1/x button then this calculation is not too difficult. If you don’t have that function on your calculator, or if you don’t like formulas, check out the calculator below.

Using the Calculator

The calculator can be used for 2, 3 or 4 speakers wired in parallel. 

Simply type the impedance of each speaker into the white boxes (or use the drop-down values). Use N/A for unused speakers in this calculator. The total impedance will be calculated for the entered speakers.

Also calculated for each speaker is its percentage share of the amplifier’s output power. This is useful as power sharing is a consideration when using speakers with different impedance.

“Power Differential” is the final calculation. This calculates in dB (decibels) the power level difference between the highest and lowest power as it is shared across the speakers. This shows the power level difference when using speakers with different impedance.

Amplifier Power Calculator

The bottom section of the calculator helps in matching the speaker combination with your amplifier. This is not necessary if you only want to know the total impedance and/or the power ratios.

However if you are connecting these speakers to your amplifier, it may be helpful to input the amplifier power and the associated speaker impedance. In the specifications for your amplifier, it should say something like:

Amplifier power: 80 watts continuous average power @ 4 ohms (2 channels driven, THD 0.08%, 20Hz-20kHz)

This tells you the maximum continuous power the amplifier will deliver into a 6 ohm load is 80 watts. In the calculator below, for this example, you type in 80 for the power and 6 for the impedance. Be aware, some specifications state RMS power rather than continuous power. These are effectively the same.

The calculator will display the effective power of the amplifier for the calculated total impedance of the series speakers. Also displayed (under each speaker’s power %) is the actual maximum power the amplifier will supply each connected speaker. A comment on the suitability of the calculated total impedance for your amplifier is also provided.

Download Calculator
as Excel File
Prices in US$

Note: the calculated output power for the amplifier is based on a theoretical “ideal” amplifier. In practise, your amplifier may produce slightly more power.

Further Reading

This calculator will help you understand the total speaker load on your HiFi amplifier. For a better understanding of this and what to do about it, read the articles How do I Connect Multiple Speakers to my HiFi Amplifier and How to wire four HiFi speakers or How to connect 2 speakers to one amplifier or watch the video in the article Understanding Speaker Impedance.Also see How Multiple Speakers Share Power for further details about the percentage power calculations. For more details about the effective amplifier power at higher impedance loads, see How Impedance Changes Amplifier Power.

Please Note: all these calculations are for connecting manufactured speakers (boxes). They are not used when building your own speaker boxes and connecting multiple speakers in a cabinet using a crossover circuit. A crossover splits the signal into different frequencies for each of the speakers and makes the total impedance calculation complex (as impedance is frequency dependent). That is why speaker designers get the big money, and as installers we benefit from their expertise.

If you need further advice on connecting speakers (boxes) in parallel, please read the FAQs before submitting your question. You may also find an answer in the comments below.

Please Note: During the Covid-19 pandemic I'm busy with a number of streaming projects, and have very limited time to attend to this website. I'm currently taking up to a week to answer questions. Sorry for any inconvenience.

Disclosure: If you buy through this Amazon USA link Geoff receives a small commission from each sale.
European and Australian readers can use the links on the side panel - Thanks for the support

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We are building 2 boxes with 8 4″ full range speakers and 2 12″ woofers in each. The 4″ speakers are 8ohms. Here’s our dilemma… How can we wire the 8 4″ 8ohm speakers and end up with an overall impedance of 8ohms(not counting the 12″s. Those are fine.)? We need to get as close to 8ohms as possible. Thanks in advance.

hello sir i got 8 speakers i wanted to connect them to my amp (4 to 8 ohms and 360 watts) i was gonna connect them to 1 channel since the 2nd channel is broken every channel got left and right (devided the speakers to each side ) the speakers : 2x(6ohms-45watts) 2x(4ohms-80watts) 2x(4ohms-60watts) 2x(4ohms-30watts) the amp : onkyo(model:A-08) 4 and up to 8 ohms per channel-360 watts can you tell me if its ok to connect them to the amp and if it is how should i do it Series or Parallel thanks for helping in advance 😀 best… Read more »

hello geoff
thanks for your help but the amp is a sterio amp (left and right )
there is 2 channels A and B
i wanted to connect them to A channel only with left and right (4 at the left side and 4 at the right side )

yes perfect it sound great
thank you alot for your help i wouldn’t have done it without you my kind friend
best wishs to you in your work
john gazoulie

Hello Geoff,
Is it possible to take 8 8ohm speakers and turn them into a 2ohm load, my amp is a 1ch 2ohm stable amp so I need one single wire at the end, I tried to do some calculations and I couldn’t figure out a way to get it below 4ohms, if you could help that would be great, Thanks

Hi Geoff,
I’m not an expert and I must realize a musical background in a shop.
I plan to buy a Marantz M-CR611 that writes in the back from 4 ohm to 16 ohm
In the specification sheet is written 60W 6 Ohm (2 channels) that means probably 30W 6 Ohm on 4 channels.
I plan to buy also 4 pair of speakers Yamaha NS-IC600 8 Ohm
I think is better to connect the 2 speakers in parallel for each channel, what do you think?
Thank you.

Hi Geoff……. I have two sets of 15 inch subs one set is dual voice coil 2 ohm, the other set is dual voice coil 4 ohm, how can I wire them all together 2 ohm if possible……..

Hi Geoff: I am using an Onkyo TX-RZ800 (135 watts per channel x 2 into 8 ohms) to power a 2 channel speaker setup. I will have 4 Polk Audio rc80i (8 ohm) speakers in-ceiling. How can I maximize power output to the speakers? My thoughts are to run these speakers in parallel which should decrease resistance to 4 ohms (which the amplifier can handle) and which should bring current to approx. 225 watts or so. My other option is to hook one pair up to the front speaker outputs and hook the second pair up to an assignable output… Read more »

Hi Geoff,

Like all your other requests I’m in need of help as maths or physics were not my strongest subjects. I have a Yamaha A3050 av Reciever and am running a centre, two front and 4 ceiling speakers. The two front speakers are KEF Q900 towers, the 4 ceiling speakers are Jenson ceiling speakers 6 ohms each. The centre speaker is an old 8ohm Onkyo model. I am also using the Reciever to run a separate zone out doors which will only be running 2 Jenson ceiling speakers. What’s your recommendation on wiring this set up?


We have 12 Bose 251 speakers of 8 ohms each, 6 speakers for channel 1 left and 6 speakers channel 2 right in ceiling but I’m not sure regarding for wiring if its series or parallel they make with the contractor. But they use home theater receiver amplifier and is not working properly. So my question is what kind of amplifier is required?


What is the best way to wire my four Control 65 P/T speakers to my JBL 2120 Amp/Mixer?

The speakers are 8 ohms each. From what I have learned from your articles, I plan to wire them in parallel.



Excellent. Thanks for your advice.

I have a 6/8 ohms amplifier YAMAHA RX 479 – 80/115 watts.
I want to connect the surround channels with serial speakers. 1 speaker 60 watts 3 ohms + 1 speaker 15 watts 8 ohm.
Is that a good choice. I know the 15 watts speaker will go louder than the 60 watts one but it’s just for surround, I listen to decent volume in surround. My question is: is the receiver protected this way from damage?