How to Find out What Size Speakers Fit My Car?

Thinking of buying new car speakers?

The car speakers market will see a huge growth in five years. We're already seeing the progress today. HARMAN, a key player in the industry, recently launched its JBL car audio equipment line in India.

And as more car sound systems pour into the market, the more choices car owners have when it comes to replacing their factory speakers.

However, even with the vast selection of products, it still isn't easy to choose which one will best suit your car. Not every speaker is the same size, making incompatibility a huge issue.

So how do you determine what size speakers fit your car?

Read on to find out!

Take the Measurements of Your Car Speakers

Want a clear-cut way to know what size of speakers will fit in your car? Measure the one you're trying to replace. Here are the measurements you need to get:

Speaker Diameter

The outside diameter is the distance across the face of the speaker. You just need to measure the length between one end and the other to get the outside diameter.

The most common sizes of OEM speakers today are 5-inch, 5.25-inch, 5x7 inches, 6.5-inches, and 6x9-inches. You'll find other sizes as well, such as 3.5-inches, 4-inches, 4x6, 4x10, and 6x8-inches.

The 6.5-inch speaker setup is one of the best out there due to the number of configurations you can do.

Note that the size usually denotes the diameter, but it's more of a category than an exact measurement. The actual diameter varies according to the speaker design.

This normally doesn't follow the standards. Rather, manufacturers alter the design of the speakers to fit in the overall car's design.

Another measurement you need to get is the cutout diameter. This refers to the mounting space size. You'll need to measure the width of the basket underneath the speaker flange.

car speakers size

Mounting Depth

This refers to the distance from just below the speaker flange to the base of the magnet. This is important because you wouldn't want your new speakers to bump into the inner construction of the car.

Mounting spaces on car doors also have limited available clearance. If you buy new speakers that are deeper, however slightly, they may not fit at all.

Mounting Height

You measure the mounting height from the bottom of the flange to the highest point of the speaker. Knowing this information will prevent your speakers potentially bumping into grills and such.

This also allows you to get a spacer ready when the tweeters of the speakers are protruding.

Mounting Screw Width

You might also want to measure the mounting screw width, but it's not paramount in some cases. You or a professional can always drill new holes to accommodate new car speakers.

Moreover, some speakers have elongated mounting holes, which make it unnecessary to drill new holes.

Installation Space

You'll find the installation spaces of your car speakers on the door panel, back rear, and front rear. Although you'll get all the measurements you need in a speaker, it doesn't hurt to measure the holes as well. These will give you an idea of what size of speakers they can accommodate.

You shouldn't have any problems with a new speaker when you have the correct measurements. In the case that you can't get them, follow the next tips.

installation space

Get the Measurements via Another Method

If measuring your car's original speakers is not possible, or you just don't want to bother doing it, consider other methods to get accurate measurements.

Speaker Brackets

You can get recommendations for speaker sizes on your car's speaker brackets. Check them if they have markers indicating the speaker measurements that fit in them.

If you can't find markers, your car probably doesn't have this neat feature. Not every model has speaker size markers, so you might have to follow the other tips.

car speaker brackets

Car Manual

If you want the most reliable source of information about your car's speakers, get the car manual. Flip to the Audio Systems section or its equivalent to checking the OEM speaker size. It should also offer a guide and some tips on what other sizes you can try out or if the system is expandable.

You'll most likely find a copy of the manual of your car model online if you can't yours.

No Measurements? Just Ask

You can still buy new speakers even when you don't have the means to get the measurements. All you need to do is ask.


If you want to be extra sure you're getting the right speakers, have a professional look at your car. You may go to a local store and have a knowledgeable salesperson determine the right fit. As a bonus, you can ask any questions about speakers in general or specific products.

While you're in the shop, you might as well buy and have them install the speakers for you. This comes with a price, but if you bought from them, they'll charge a minimal fee.

If you prefer buying online but don't want to install them, take them to an automotive store. The installation fee will cost more. In exchange, you can have the peace of mind from the fact that expert hands are working on your car.

Speaker or Manufacturer

You can take a chance and see if the speaker you're eyeing has a list of compatible models. If not, shoot the manufacturer an email. If they're helpful, they should be able to answer if the speakers would fit in your car or not.

Online Tools

There are online services that can give you recommendations depending on your vehicle. An example is this tool from Crutchfield, which will ask for your car's information.

You'll need to enter the year of your car's release, the make, the model, the body (if applicable), and other options. Afterward, you'll receive a comprehensive list of products that you can install.

It's an easy and straightforward way of getting a list of car speakers that fit on your car. You won't even need to get measurements.

That's about every way of knowing which speakers are compatible with your car. However, size compatibility is not everything that you need to consider.

Things To Consider Before Buying Car Speakers

Aside from making sure that the speakers will fit, you also have to ensure its compatibility. It should work together with your current system, and it should last long enough for its price.

Speakers Weight

Most people won't even consider the weight as it's not an obvious factor. However, the weight of the car speakers matters when you're putting them in a sensitive area.

Door panels can handle less weight than the rear in the back or the front. When choosing a system, make sure that the speakers in the door panel weigh less than the ones in other areas.

Woofer Quality

When buying speakers, remember to examine the quality of the woofer. For great-sounding bass, look for a woofer that has stiff and lightweight materials.

Manufacturers often use polypropylene with other materials to enable a more accurate bass response. You can also look at other options with woven fabrics, wood, ceramic, and more.

Speakers woofer quality

Surround Materials

Look for speakers with rubber surrounds if what you're after is great sound quality and longevity. You'll want to steer clear of materials like foam and paper, which you'll find in factory speakers. These materials deteriorate, affecting the sound quality negatively.


Speakers require power, on which the sound they will deliver will depend. How much sound speakers are able to yield refers to sensitivity.

Factory-installed stereos are usually low-powered with 15 watts RMS per channel or less. For this type of stereos, buy speakers with high sensitivity (over 90 dB). A high-powered system (16 watts RMS or more) best matches with low-sensitivity speakers.

To make sure that your stereo and speakers work together, consider buying a new stereo for your car as well.


The RMS rating indicates the amount of power that a speaker can handle continuously. Speakers' power-handling ratings are in ranges, in which the higher number is the RMS.

If you have a low-powered system, you won't need speakers that can handle a lot of power. If you have a high-powered system, your speakers' power-handling should be close to the output of the power source.

To get the best experience out of speakers, choose the ones that have an RMS matching the power source. The level of the power source (receiver or amp) should be in RMS or continuous watts.

Remember to ask an expert if you're having trouble with looking for the best car speakers. As we've discussed, there are a lot of factors to consider to make sure that you're buying the perfect fit.

Learn More About Car Speakers

Buying is not as simple as one would think. You can't march in a store, choose what suits your mood, and go home with new car speakers. You have to do a lot of considerations if you want to go home with the best and the perfect speakers that fit your car.

If you're ready to replace your factory-installed speakers, check out our blog now! We review car speakers, the best amps, and more to give you the best recommendations for your sound system.