What Size Speaker Wire Is Right? The Right Gauge, Type, And More

Wondering what size speaker wire you need? You’re in the right place!

In this guide, I’ll show you the proper gauge and type of speaker wire you need. I’ll also cover a lot more, too:

  • Simple & quick rules of thumb for speaker wire size if that’s all you need to know.
  • Speaker wire gauge and the American Wire Gauge chart explained.
  • Understanding copper clad aluminum (CCA) vs pure copper wire so you don’t get ripped off.
  • Solid vs stranded wire – and why you don’t want solid for speakers.
NEW! I’ve now added a speaker wire gauge calculator and a simplified speaker wire gauge chart to make it a breeze. The article has also been updated.

General tips: What size speaker wire do I need?

Speaker wire size quick guide
  • For most low power home or car speakers (not subwoofers) 18 gauge (18AWG) is fine. 18AWG wire is good for about 50 watts for 4 ohms and 100 watts for 8 ohm loudspeakers up to 50 feet (15 m) or 100 feet (30 m) respectively.
  • For higher power systems or longer lengths, 16 gauge is a great choice.
  • For longer lengths (50-100ft)/(15-30.5m) you’ll need to go up 2 gauges (14 ga.) to avoid losing power. Very long lengths of speaker wire lose a bit of power over the long distance due to resistance. Using larger wire can help reduce or avoid this. (Use my speaker wire calculator to make it easy)
  • A higher speaker impedance value (ex.: 6 or 8 ohm speakers) draws less current (lower amps) than lower impedance speakers. Therefore you often can use a thinner wire for them as you’ll see.

Simple “everyday” wire size table

Wire Size Recommended For
18 AWG Car and home speakers up to 25 ft with average power levels (50W RMS and below).
16 AWG Longer speaker runs for car & home stereo speakers or short runs under 20 ft for 75-100W. Moderate power subwoofers (under 225W) with short lengths.
14 AWG Long (100ft+) speaker runs or higher power applications such as high-power 2 or 4 ohm subwoofers with a short length.

In most cases for everyday listening at medium or low power levels (50W RMS or under), 18 gauge (18AWG) wire is what you need.

It’s a good compromise between price and power handling as it’s usually affordable and easy to find.

How to find the correct size wire for ANY length or speaker system

The correct gauge speaker wire you need is based on 3 things:

  1. Your stereo or amplifier’s power output.
  2. The speaker’s impedance (Ohms) rating – also called the nominal impedance.
  3. The cable length needed for your speaker system.

However, I’ve made it easy for you: You can use my speaker wire size calculator or speaker wire size chart sections provided below.

SPEAKER WIRE GAUGE CALCULATOR

speaker wire gauge calculator image

My speaker wire gauge calculator will recommend the right speaker wire gauge based on the power, speaker Ohms, and the specific length you need. This is different from the speaker wire size chart section below that provides lengths based on the speaker Ohms only and doesn’t need power ratings.

You can play around with different power amounts, lengths, and speaker Ohms to find the best speaker wire gauge for your audio setup and avoid spending more money than necessary.

HOW TO USE:

  1. Enter the following:
    • The wire length you need. This can be whole or fractions (5 ft, 2.6 ft, etc.).
    • RMS/continuous power for your amp or stereo.  (Do not use “peak” or “max.” power ratings.) 
    • The speaker impedance in Ohms (Ω).
  2. Touch the button to get the results.

The wire calculator will output:

  • The smallest wire size with 5% or less power loss for both copper and copper-clad aluminum (CCA) wire.
  • The power loss across the wire, in Watts, at maximum power output.

SPEAKER WIRE GAUGE CHART

speaker wire gauge chart diagram

The chart and tables above are handy if you aren’t sure about your stereo or amplifier power. You can estimate the length of wire you can use without losing a lot of power (at maximum stereo or amplifier output) knowing only the speaker Ohm rating.

Both copper wire and copper clad aluminum (CCA) wire charts are provided. Because aluminum has a lower conductivity than copper (higher resistance per foot), the length will be shorter than for real copper.

Note: Be sure to check my additional tips further below as they can help you save money.

Choosing a speaker wire gauge for long distances

What if you need say 50ft or even 100ft of length? In that case, a general rule of thumb is to double the size by choosing a wire thickness 2 sizes up from what you would use for shorter distances.

The gauge number (the electrical conductor size as per wire standard charts) increases or decreases by an even number (by adding or subtracting 2) as odd numbers aren’t commonly used.

Example: 18AWG wire will lose about 4 watts at maximum power if it’s 50ft long. To avoid this when moving from a shorter wire length, we can pick a speaker cable 2 sizes up: 18 AWG -> 16 AWG -> 14 AWG.

Tips on using smaller speaker wire and saving money

As real copper wire is more expensive these days and because most people don’t drive speakers at full power, here are some tips to keep costs down:

  • If you rarely use your amp or stereo output above 50%-60% power, you can go down one wire AWG gauge. This is because you’ll never reach the wire’s current capacity if you don’t use maximum power.
  • Have extra wire you’d like to put to good use? You can double-up or even triple-up smaller gauge wire to get the same gauge as a thicker wire size. (Example: using two lengths of 18AWG you have lying around in parallel to approximate 16AWG wire).
  • For surround sound and center channel home theater speakers, you shouldn’t spend a lot because their power needs are usually fairly low.

Is oxygen free speaker wire worth it?

No, oxygen free pure copper wire will not deliver any noticeable improvements in sound or power. It’s not worth spending more money on it.

It’s a great marketing feature for retailers but the data shows that there’s an amazingly small difference in performance. Paying more is a waste of money. As long as you’re using a good quality wire with the correct gauge you’ll be fine.

The electrical signal will not have any measurable difference at the speaker end.

It is true, however, that real copper wire is better than copper coated aluminum wire as I explain later.

What gauge is speaker wire? (Wire size and wire gauge explained)

Image showing a comparison of common speaker wire gauge sizes

Speaker wire doesn’t have just one size (gauge) – it’s standardized and based on the American Wire Gauge (AWG) chart which lists standard sizes using a number.

Less commonly known as the Brown and Sharpe wire chart, the American Wire Gauge chart has been around since 1857. It specifies sizes, each with a given circular area of the electrical conductor size, its resistance per foot or meter, and some other specifications.

Likewise, each AWG wire gauge has an electrical current capacity (how many amps it can handle, also called ampacity sometimes).

Diagram showing example scale sizes of AWG wire gauges 18 to 12

The AWG wire chart uses a numbering system in which thicker cable has a smaller number. Likewise, a larger number is used for smaller wires with fewer conductors.

Speaker impedance and power vs the correct gauge wire

When an amplifier supplies an audio signal with a given voltage output, speakers with a lower impedance draw more electrical current (higher amps) than higher impedance speakers. This can make a difference in the wire size you need based on the length and power carried to audio speakers.

Higher amps require a larger conductor size (thick wire) just like for power wire. By comparison, thicker speaker wire has low resistance and therefore less power lost across it at high power levels or a long cable run.

Most speaker wire sold today is made up of two conductors attached as a pair with one marked as the positive; they’re essentially the same as stranded power cable paired together. The gauges available range from about 20 gauge to 10 gauge, with 18 gauge being one the most popular.

Thin wire such as 20AWG or 22AWG isn’t very common but occasionally can be useful for lower power speakers.

Stranded vs solid conductors

Comparison of solid vs stranded wire

All speaker wire sold is stranded, meaning it’s made up of a bundle of 16-60 or more very fine copper conductors. Solid wire, however, has only one conductor. For stranded types, a thicker wire gauge uses more conductor strands with each larger than a smaller gauge.

Stranded wire has a big advantage over solid in that it’s very flexible and not prone to breaking under stress. It’s also easier to strip the insulation to bare wire with a wire stripper. It’s also less hassle to work with if using spade connectors or inserting it into a crimp connector.

Since solid core is used for home and industrial electrical wiring, you might be tempted to use some leftover house electrical wire for your speakers. However, it’s a terrible choice for that.

How much wire do you need?

Speaker wire length estimation diagram

Buying & using speaker cable is definitely one of those cases where the old advice “better to have too much than not enough” applies! You don’t want to run out because you didn’t plan ahead.

It’s always best to measure and be sure – and overestimate what you need to be sure you don’t run short.

To figure out how much speaker wire you need, my suggestion is to use one of the following:

  • A tape measure
  • A long length of string to run

Be sure to try to take curves & bends into account but don’t worry about getting it exactly right. Measure the distance and then add a few feet (an extra 2 feet or so is good) to account for curves and other little things that add up.

A tape measure works well and so does string or rope you can place along the path where the wire will go.

Mark the length, then measure it. I like to add at least 1 foot of length for each wire section for home stereo use and 2 feet each for car stereo installations to play it safe.

Figuring out how much wire to buy

When it comes to buying speaker wire, one thing to know is that it adds up fast! Here are two examples to show what I mean:

Speaker wire length example #1

Home stereo example:

  • Front speaker lengths measured: 2 x 6 ft
  • Rear speakers measured: 16 & 22 ft

Total wire needed: 6 + 6 + 16 + 22 = 50 ft (15.2m)

Speaker wire length example #2

Car stereo example: Running wire from the dashboard head unit to front door speakers and to rear deck speakers.

  • Front speaker lengths measured: 2 x 8 ft
  • Rear speakers measured: 16 & 20 ft

Total wire needed: 8 + 8 + 16 + 20 = 52 ft (15.9m)

Speaker wire is normally sold in rolls such as 25ft, 50ft, and 100ft, although some retailers offer it by the foot as well.

Precut lengths are also available sometimes, too. Those are usually around 6, 12, or 18 ft. However, more often than not you’ll save money by buying a good quality by the roll.

**Rember this rule: never take chances with speaker wire length – don’t guess. Buy at least a little bit more than your estimate.

Copper-clad aluminum vs copper speaker wire

Copper clad aluminum vs copper speaker wire illustrated diagram

Copper-clad aluminum (CCA) wire has, in the last few years, become more and more common as the price of copper has gone up. It’s one of those “little things” you might not know when buying that companies aren’t telling you.

Unlike pure copper wire, copper-clad aluminum uses an aluminum wire core with a thin copper plating. From the outside, it misleadingly looks the same because of the plating.

Aluminum offers a lighter weight and lower cost than copper, so at first it may seem like a great way to replace the more expensive copper options. However, there’s a problem.

Aluminum has only 61% of the conductivity of copper (in other words, it has 39% more resistance) meaning it will take larger aluminum wires to get the same power handling, capacity, and resistance value.

Everyday use & what to know

In most cases like average listening & typical power levels, it’s not really a problem in day-to-day use. However, if you’re going to drive speakers at higher power levels or want the absolute best for your money, you’ll need to be sure to look for packaging that specifies the wire is 100% pure copper.

To get the same performance as true copper wire when buying CCA speaker wire, move up one gauge in size. For example, to replace 18 gauge copper wire, use a 16AWG or 14AWG CCA wire.

More great articles to read

Your suggestions and feedback are welcome!

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Post a comment below or you can reach out via my Contact page. Thanks!

Your comments are welcome!

  1. Cool Marty thanks for explaining speaker impedance and wiring so clearly

    Doesn’t stranded wire also have less resistance as the electrons travel faster around the outside of a stranded wire as opposed to one solid conductor

    Reply
    • Hi Eric. I think you’re referring to the skin effect? That’s only really an issue at higher frequencies outside of the audio range. Stranded wire will actually have more resistance than solid wire of a similar size.

      If you look at the ampacity (amperes) rating for stranded vs solid wire you’ll see what I mean.

      Best regards.

      Reply
  2. Great website, but how do I access your SPEAKER WIRE GAUGE CALCULATOR?

    My speaker wire gauge calculator will recommend the right speaker wire gauge based on the power, speaker Ohms, and the specific length you need. This is different from the speaker wire size chart section below that provides lengths based on the speaker Ohms only and doesn’t need power ratings.

    I have clicked on everything and can only see the speaker wire size chart.

    Reply
    • Hi, it sounds like your browser/ad blocker/security settings/etc. are preventing Javascript from loading. My calculator is definitely there and working as I tested it on Chrome, Edge, and FireFox on both desktop and mobile. I’ve checked again and I had not problems at all using it.

      So it’s likely something related to your browser or settings, etc. You can also find it separately here, but you’ll need to unblock Javascript from working: https://soundcertified.com/speaker-wire-gauge-calculator/

      Most tools such as crossover, speaker, or other calculators require JS to work. Best regards.

      Reply
  3. Hello. I may Have missed it in the reading of your article but, can you run 14 gauge about 50 feet and then split it up 2 different ways and run 18 gauge for a run of 90 feet and then a run of 100 feet? I will be using pure copper, stranded. I have 2- 8 ohm speakers & the amp is 125 watts per channel. Thank you.

    Reply
    • Hi there. We could break this down into sections and then check it that way. For example, for the 90 and 100 ft. sections (125W total, two 8Ω speakers), we’d have about 1/2 the power (62.5W max. to each speaker). Using the calculator, a 100ft, 62W, and 8Ω gives a recommendation of 12AWG wire.

      So I wouldn’t recommend 18AWG on the end sections. If you wanted to, 14AWG or maybe even 16AWG would be good if it’s low to moderate power use (if you’re never going to drive the speakers at full power). You’ll lose a few watts at max. power especially at 18AWG.

      However, 14AWG is the smallest I’d use on the 50ft length. That’s 50 feet / 125W / 4Ω (total, 8Ω parallel) for that part, which gives a recommended size of 12AWG. Again here you can get by with 14AWG if you’re not driving the speakers at full power.

      Reply
      • Yes sir. Thank You for your reply. After reading your reply, I realized I did not give a proper explanation. If I run 14 wag, 4 conductor, meaning, two conductors for each channel, (of which I have 2 open channels on amplifier at 125 watt each), running the 14-4, 50’ and then taking each channel, 2 separate ways, one at 90’ & one at 100’, with 18 awg, would that be ok? And, is it ok to use wire nuts to make the splice or, should I crimp, solder or, “screw down” terminal the splice? Does solder cause reduction in quality? Thank you.

        Reply
        • Hi, yes that’s what I thought you meant already, so you can refer to my previous reply. It will still be the same as far as I can tell from your description.

          Wire nuts aren’t very good, honestly, and can come off later. Crimp connections are very good and easier than soldering, so they’re good (with the correct size and a good crimp connection). Soldering is the best possible, just that you’ll be sure to use electrical type solder and a good iron to get the solder to flow well.

          Solder makes an excellent connection and there’s no reduction in quality for a good solder connection.

          Reply
  4. fantastic article you really covered all the bases. cleared up a lot of myths in the process and making my wire selection easier and less costly.

    Reply
  5. Hi Marty,

    It’s puzzled me for the longest time for having a proper stereo speaker connection. I always took the longest run and subsequently cut the cable the same length for the other channel even if it was a small distance from the receiver to that speaker. I’m talking about a 25 ft for the furthest channel
    My reasoning is to match the resistance and impedance of both channels.
    Is it important?

    Reply
    • Hi Hans. For speakers and audio at reasonably short lengths, it generally doesn’t matter. The difference in resistance between the two lengths of wire would be negligible.

      However, in some cases it can make a bit of difference:
      – Very high power being delivered to speakers (more electrical current = more loss in the wire is possible, mainly at full power)
      – If the wire needs to be larger to reduce resistance in Ohms (generally for very long lengths of wire, say 50+ or 100 ft etc.

      Even then it’s usually minimal power loss across the wire, say a few watts for example. In terms of sound it won’t have anything noticeable effect for reasonable lengths of wire.

      I generally cut speaker wire close to the same lengths when possible but that’s more for reducing waste from a large roll as well as keeping things neat.

      You can actually see what I mean by using my speaker wire gauge calculator in the article above. It will estimate power loss etc for a given wire length, power, and wire size.

      Best regards!

      Reply
  6. Hey Marty! I want to thank you because you were a life saver for me about 2 years ago, with questions I had for an install. Now with a new car, installing some new sound upgrades, your site replaced Google search! Appreciate your knowledge & thoughts you’ve put into this. Anyway, I have Kicker 6 1/2 inch components for my front door. The crossover that came with them are pre-wired using 20 or 22 gauge wire. The recommended wire size to power my speakers, based off length/2000 watts rms of amp/ohms suggests that I use 10 gauge. So my question is, as for wiring my components, how do I approach this? From my understanding, running 10 gauge to 20 gauge can’t be good. BTW, these front door components, I’m wiring straight to my amp. I’m not using any of the factory wiring.
    Thanks Marty!!!

    Reply
    • Hi again Rob. Very happy to hear my site is helping you and that you like it. :)

      There’s a glaring issue I see and that I suspect you’re going by the wrong power numbers. 1) 6.5″ speakers can’t handle that kind of power (2,000W) and 2) the only amps that can deliver power in that range are normally subwoofer amps.

      You should go by the RMS or continuous power per channel, not the “peak” or “max” power ratings which are misleading. I don’t have the amp model number so I can’t comment specifically. You’ll most likely need 14AWG-16AWG size wire for 6.5″ at the most (in most cases). If you can give the amp model etc. I can clarify more.

      Best regards.

      Reply
  7. LMAO! Wow! Well, I’m still a noob. You explained very clearly using RMS in the calculator, my mistake.
    Thanks for the quick reply. It’s the Pioneer GM-D9705, which I know you’re familiar with from your write up. 4 ohms 75 x 4 & not sure off the top what the sub channel is.
    The crossover for my 6.5 components is pre-wired or hard wired, 1 wire for power, 1 for tweeter & 1 for the 6.5. So is it ok to run a 14 gauge wire from the amp straight to 20 gauge (crossover wire)? I hope I worded that correctly. Thanks Marty

    Reply
    • Hi, yes it’s ok to use 14AWG although in reality if you’re not using it at full power normally you can go down a size in wire if you like. I’m a bit surprised they’re using only 20AWG on the crossover. It’s usually about 18AWG.

      Best regards.

      Reply
  8. Thank you Marty! It might be 18awg. I’m still fairly new at this but thank you for your reply! You’ve been a huge help bro!

    Reply
  9. You explained everything very well but still can’t figure out what gauge wire to use for my rear speakers.
    I have got a Soundbar with two rear 4 ohm speakers. It’s Sony hts20r home theatre setup. The rear speakers already have 6-7 meters of wire but its not enough for my room. Each rear speaker needs 15 meters wire to connect to the main unit which is the subwoofer. According to the calculator 12 AWG wire is suitable for it but it costs a lot here. Can i use 16 AWG wire instead because it’s cheap and easily available.
    I am also confused because the company wires have 6-7 meter length and have 24 gauge. According to the table 24 gauge wire can be used for max 1.2 meter.

    Reply
    • Hi Aman. Yes, as I mention in my article already, in practical terms if you’re not using the speakers at 100% power output from an amp or stereo you can go down a bit in wire gauge so don’t stress over that. The wire gauge recommendations are based on maximum power for a given speaker Ohms.

      Feel free to use 16AWG if you like. If the wire you have is truly 24AWG, that’s WAY too small – that’s almost as small as telephone wire conductors. However, it depends on the power output of your amplifier or soundbar.

      What is the RMS or continuous power rating for it? If it’s only a few watts it’s probably ok, but generally you’d want no less than 20AWG. 24 gauge is unusually small!

      Reply
      • Thank you Marty! I don’t know the RMS for each speaker but the system can produce a total output of 400 watts. It includes a soundbar (center, left, right), subwoofer and two rear speakers. There is no label for each speaker output.

        The wires are so thin that I cut one by mistake with hammer. Is it okay to splice the wire to join it again.
        Does splicing reduces audio quality and will it be noticeable if i use speakers at 50-60 % ?

        Reply
        • Hi Aman. I don’t think 400W is the actual RMS or continuous power, so it will be much lower than that in reality. Yes, you can splice or re-connect the wires so don’t worry. If you can use crimp connectors that’s easier, but if not it’s ok as long as it’s a solid and clean connection.

          Splicing does not affect sound quality unless there’s an unusual problem so don’t stress over there. If you have access to a soldering iron that’s the best way with crimp (butt) connectors being the 2nd option for the best connection.

          Best regards.

          Reply
          • Thank you Marty for all the help! I was so confused which wire to buy. I went to a shop and they told me if i splice the wires it will reduce the audio quality and could result in short circuit. The only option was to change the entire wire. Now i can go for sure… and thank you again for taking the time.

  10. I’ve been having all sorts of issues with upgrading the audio in my 2021 mustang. It seems that my biggest mistake was purchasing the premium 9 speaker system that includes an amp. It sounds awful, so I decided to get rid of it completely. I would like to run an audiocontrol dm-608 that has channel summing. I used forscan to shutoff the factory EQ so that the high pass filter would be removed from my rear channel. I am installing 3 amps ( 2x100rms @4ohms ),
    ( 2x100rms @4ohms ), ( 1x500rms @2ohms ) and 2 component sets (front/rear) with subwoofer. Should I have just added a second head unit instead of the dm-608 ?

    Reply
    • Hi, ideally yes – you’re generally often better off with an aftermarket head unit, but like a lot of things it depends on the compromises you have to make and what’s ok for you.

      If you’re able to use an aftermarket head unit you’ll avoid the issues related to the factory system like the separate audio channels. Also you can get an affordable head unit like from JVC/Kenwood with great sound, a 13 band EQ, and tons of features.

      The AudioControl unit is really nice but that’s a lot of money to invest in just the signal path alone. Personally, I do try to bypass factory amplified systems like you have when possible.

      Reply
  11. Hi Marty,

    I recently upgraded my Yamaha amp from a 95watt rms per channel to the A3020 amp as the 95watt amp was all I could afford at the time. Form which I was and still am, running a set of Whafedale AT 500s. They are beasts with 200 watt nominal power handling and state 6ohm and the instructions say they will run on 8ohms. They feel a little under powered on the newer somehow (165 watt rms amp) although it could be my imagination since I moved from a smaller flat to a house with nearly 1.5 times the area they are in. I have set the new amp at 6ohms or less, but it does have an 8ohm setting. First can I ask if I should be using the 8 ohm setting instead? Secondly, given that I need about 9 meters of cable from the amp, what gauge wire would you recommend I use. I fear the older cable (20 years old) oxygen free (I was naive at the time) should be replaced. (Any thoughts welcome) I think it is 16 awg, but hard to tell since it is a ribbon cable. I was thinking of getting a power amp as well, but a little worried about moving from an AB class amp to a Class D to get more power (crown drive core xls). Any advice you migh have would be greatly appreciated. Thanks

    Reply
    • Hello Des. 1) You’ll use the 8 ohm setting in this case. 2) You can use the speaker wire gauge calculator in the article as I’ve provided it for this reason. Just input the power rating, length, and speaker ohms and it will show you what will be good.

      You can play around with different lengths or etc. as needed to see what that will change.

      If you’re thinking about getting a class D amp, if it’s a decent brand it should be a good option with more power for the money and good sound. Unless you’re a bit of an audiophile then class A/B may be more your style. But I think you’ll be pretty happy with a good class D amp. Best regards.

      Reply

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