How to Make Your New Car Radio Fit

Two men in front of a van with a measuring tape

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When a new car radio doesn’t fit correctly, there are a handful of different factors that might be at work. If the new car stereo doesn’t fit because it’s the wrong size, then a car radio fit kit will help in certain circumstances. For instance, if you bought a 1 DIN car radio to replace a 2 DIN car radio, then an installation kit will do the trick. The opposite usually isn’t true, though, and fit kits can even cause issues in some circumstances where some aftermarket car stereos won’t fit into certain installation kits, and other combinations can lead to a messy looking dashboard.

When a New Car Radio Doesn’t Fit

Factory car stereos come in all sorts of bizarre shapes and sizes these days, but there are three common form factors for aftermarket units that are all based on a single DIN standard. The DIN standard for car radios specifies a height of 50mm and a width of 180mm, with no mention of depth.

Measured in inches, head units that conform to the DIN standard are roughly 2 inches tall and 7 inches wide, despite the fact that 180 mm actually converts to 7.08661 inches. That actually falls somewhere between 7 5/64 inches and 7 3/32 inches, but there’s usually enough wiggle room that a few hundredths of an inch here or there don’t matter too much.

The other two common head unit sizes are also taken from the DIN standard. The largest is 2 DIN, which is simply 4 inches tall and 7 inches wide, then there is the less common 1.5 DIN, which is about 3 inches tall and 7 inches wide.

Just looking at those three common car radio sizes, it’s easy to see how you could end up with fit issues at a very basic level. Head units built to the 2 DIN or 1.5 DIN specifications simply won’t fit in a slot meant for a 1 DIN head unit, and trying to put a 1 DIN stereo in the space afforded a 2 DIN OEM unit will leave an ugly, gaping hole.

Solving Car Radio Fit Problems With Installation Kits

In most cases, the solution to a new car radio that doesn’t fit is a car stereo installation kit. Unlike aftermarket head units, which are platform agnostic and designed to work in a wide variety of cars and trucks, each installation kit is purpose-built for a very specific range of makes or models.

The classic use for a car radio installation kit is to allow a 1 DIN aftermarket radio to fit into a dash that came with a 2 DIN or 1.5 DIN factory stereo. This type of kit includes a slot and mounting hardware that will fit any 1 DIN aftermarket radio, while also fitting perfectly into the dash of the specific make, model, and year of your vehicle. In many cases, this type of kit will also include a storage pocket to make use of the extra space.

Car stereo installation kits can also solve issues where an aftermarket radio won’t fit due to the factory radio being strangely shaped.

When a Car Radio Won’t Fit in an Installation Kit

Despite the fact that aftermarket radios conform almost uniformly to 1 DIN, 1.5 DIN, or 2 DIN dimensions, there are circumstances where you may find that an aftermarket head unit doesn’t actually fit in an installation kit that it is meant to work with. This is usually due to the slight difference between the actual DIN standard, which is measured in millimeters, and the accepted US standard, which is given in inches since they don’t match precisely.

If an installation kit from one manufacturer doesn’t work with your new head unit, there is a good chance that a kit from a different manufacturer will. This isn’t a terribly common occurrence, but if the make and model of your car is relatively common or popular, you will often be able to head off potential issues by checking out Internet forum conversations to see if anyone with your specific car has experienced issues with a particular car stereo kit manufacturer in the past.

In some cases, it’s also possible to make an aftermarket head unit work in an ill-fitting install kit — or make an ill-fitting install kit fit in the dash of your car — by shaving off a tiny bit of material with a dremel tool, but that goes above and beyond what most people are willing to accept when installing a new car radio.

When a Car Radio Fits the Installation Kit but Doesn’t Look Clean

One issue that people often run into when using an installation kit is that, depending on the design of the head unit, the final installation may not look clean. The issue here is that aftermarket car stereos are typically designed to use a bezel, since the fact that they are more or less universal means that they won’t fit perfectly in the dashes of most vehicles.

When you install an aftermarket head unit into a dash slot that it more or less fits, using the included cage, the face of the radio sticks out far enough to snap the bezel on. This results in the type of aftermarket installation most people are familiar with, and while it won’t ever look factory, it doesn’t leave any ugly exposed gaps.

When you install an aftermarket head unit with a dash kit, the head unit is often bolted to the kit via ISO mounts rather than using the sleeve. This can result in a much cleaner look if the factory bezel plays along. However, there are many situations where the factory bezel doesn’t cover the gaps between the mounting kit and the aftermarket radio, which can result in a less than attractive final product.

In most cases, an ISO-mounted head unit will not stick out far enough for the aftermarket bezel to be installed and snap on securely. Depending on the specifics of the vehicle, it may be possible to loosen the mounting bolts and slide the radio out far enough to attach the aftermarket bezel or slide it back flush with the dash so that the gaps are less obvious.

Making Sure a Car Radio Will Fit

If you’ve already bought a new car radio, and you either can’t or just don’t want to return it, then you’re going to be stuck trying to find some way to make it fit. For those who haven’t yet pulled the trigger on a new head unit, there are a few ways to make sure that the new radio will be a good fit.

In many cases, the easiest way to make sure that a new car radio is going to fit is to actually measure the old car radio. Since most radios are either 1 DIN, 1.5 DIN, or 2 DIN, this is actually pretty easy to just eyeball. But to make sure, you can just pull out a tape measure and check. If it’s about 2 inches tall, then it’s a 1 DIN, if it’s about 3 inches tall it’s a 1.5 DIN, and if it’s about 4 inches tall it’s a 2 DIN.

If you’re buying a new car stereo as a gift and don’t have access to the vehicle, or if the dash is designed in such a way that it’s difficult to tell at a glance how tall the stereo is, then the safest way to make sure you buy the right size replacement unit is to consult a fit guide.

Most car stereo retail stores can help you with this, but the information is also available online from retailers like Crutchfield and Sonic Electronix. Using a fit guide from a reputable online retailer doesn’t require you to actually buy from that retailer, so it’s a good way to get an idea of what will actually fit in your car regardless of where you end up buying your new head unit from.