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 crisis I'm very busy with a number of streaming projects, and have very limited time to attend to this website.. I'm currently over a week behind in answering questions and may not get to them in a hurry. 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

Nishchay (Kota, Rajasthan)

Sir i have 2 speaker of 20w 16ohm and 2 speaker of 40w 6 ohm, then how can i take them in my use with phone, and how much sound amplifier is required for them

Pinkesh (Delwada, India)

Hello sir,

I have 3 Ahuja 65 watt 8 ohms speakers and I have a amplifier output 200 watt 4ohms and 8ohms selection. How can I connect 3 drive units (speakers) to this amplifier. How can I match the impedance so that I can connect in 4 ohms or 8 ohms.


Hello Geoff, I have a question I’ve recently bought a pair of JVC Model Sp-HXZ1 speakers. The speakers contain a sub-woofer rated at 150W at 6 ohms and has the main speaker rated at 50 W 6 ohms. My receiver is a Sony STR-DH750 which is rated at 6 ohms. Wiring up the one jvc speaker with both of its internal speakers in parallel will put it at 3 ohms, which my receiver obviously cannot handle . Likewise, putting in series will raise it up to 12 ohms, which is not ideal. My question is, If I wire the speakers… Read more »

Skybuck Flying

How to calculate for this tripple voice coil each coil 8 ohms:


Best way to wire for typical amplifiers ?

Paul (New York, USA)

Hi Geoff,

I’ve got a question about a setup we are doing… we have a 1,000 sqft banquet hall, we’d like to put 8 speakers in the ceiling, 4 in each side (4 left, 4 right). What do you recommend as far a wiring and an amplifier. Mostly used for a microphone setup and music.



Hey Geoff, awesome website. I have a quick question about a 6 speaker setup I’m contemplating. It goes as follows: I have two identical guitar cabinets, 3 speakers a piece. Each cabinet runs 2 x 16ohm and 1 x 8 ohm speaker wired in parallel, coming out to a 4 ohm load. Cool. My thought is to wire the two outputs from each cabinet (4 ohms each) in series, combining the cabinets to make an 8 ohm load. My plan was to take positive from cabinet one and negative from cabinet two for the main output, and then cross the… Read more »

Aaron E. (Wichita Falls, Texas)

Hi Geoff, I love the website and all the information. Great stuff! In short, I’d like as much information as you can offer about my inquiry. I am using a 300 watt Tube amp – Ampeg SVT 2 PRO. Cabinet A – Ampeg SVT 410HE – 500 Watt – 4 speakers – 32 ohm each – Final impedance @ 8 ohm. Cabinet B – Self made – 2 Speakers – 175 watt each – 4 ohm each – Wired in series – Final impedance @ 8 ohm. I daisy these cabinets together – Speaker wire from amp to cabinet A… Read more »


Hiya Geoff, thanks so much for writing this article and helping all of us out. I have six eight ohm speakers and a Pyle Pro PCA3 stereo amp, with each amp rated at 75W at 4 Ohms. I’m planning on connecting three Boston CR55 speakers to each side. If I’ve synthesized this article correctly, in parallel I’d get an impedance of 2.66 ohms, and in series an impedance of 24 ohms. I’m assuming it’s a better idea to wire in series in this case, but I wanted to double-check. If my understanding is correct, having them wired in parallel would… Read more »

Josh (Greeley, USA)

Geoff, Have a interesting configuration I am attempting to implement. I will be using a Sonos CONNECT:AMP that has 55W at 8 Ohms. I will be using it to be powering 2 zones, each with a Russound ALT-126R. I will be connecting the Amp to a Russound EZB-8, which I believe wires in parallel, then out to the VCs. One zone will be connected to a single pair of stereo speakers (8 Ohms). The second zone will be connected to 2 single point stereo speakers (8 Ohms), so the equivalent of two pairs of speakers. I am trying to figure… Read more »

Jimmy (Warwick, RI, U.S.)

Hi Geoff my question is I have 6 speakers 4 are 2 ohm per coil dual voice coil speakers and the other 2 are single voice coil 8 ohm is there a way to wire for a 1 or 2 ohm load or a 4 ohm load maybe I can’t find any calculators for different voice coils and impedance. Any help will be greatly appreciated. P.s. I’ll be hooking up to my 250w or 500w per channel 2 channel 1 ohm stable car amplifier in my car. Thank you so much.