What is a Single DIN Car Stereo?

1 din car stereo
Single DIN, or 1 DIN, car stereos are easy to replace due to how many aftermarket units are available in this ubiquitous form factor. Westend61 / Getty

Single DIN is a standard that was created by the German standards body Deutsches Institut für Normung, which is where the "DIN" initials came from. The standard specifies a height and width, but not length, for car head units. So when such a unit is referred to as a single DIN car stereo, or a single DIN car radio, that means it is the height, and width, outlined in the DIN standard.

Automakers and car stereo manufacturers around the world all use this standard, which is why most head units are interchangeable as far as dimensions are concerned.

Wiring is another matter, but the DIN standard is the reason that you can replace so many OEM car stereos with aftermarket units and have them fit with almost no problems.

Although the DIN standard only specifies a single height and width, head unit manufacturers also produce devices that are twice as tall. These double-tall units are referred to as double DIN since they are literally two times the height of the actual DIN standard.

To complicate matters even further, a small number of head units are 1.5 times the height of the DIN standard, which technically makes them 1.5 DIN.

How Do You Tell If Your Car Radio Is Single DIN?

The easiest way to tell if a car radio is single DIN is to measure it. If the radio is about two inches tall, it's probably single DIN. And if it's about four inches tall, then it's double DIN. Rare cases of 1.5 DIN radios fall in between those two, and there's no such thing as a 3 DIN head unit or anything else standardized of that size or larger.

Some vehicles are trickier than others. For instance, if a dash has three vertically stacked slots that are all about two inches in height, and only one is taken up by an OEM radio, then it's probably just a regular single DIN head unit. In a case like that, it's difficult to say what they other slots were for, or if they could accommodate a larger head unit.

In most cases, blank slots above or below a single DIN head unit were originally designed to house a CD player or another piece of audio equipment. In some cases, it's even possible to find new old equipment sitting on a dealer's shelf and install a factory CD player in an older vehicle that is so equipped.

When it comes to actually replacing a single DIN head unit with a double DIN head unit, it usually isn’t possible. In situations like the one outlined above, where a dash has multiple extra slots, it may be, but the issue is still complicated. Before attempting such an upgrade, it's important to verify that the "slots" can actually be accessed and then measure the available space.

Replacing a Single DIN Car Radio

When you're ready to replace your single din car radio, the easiest option is to buy a single din aftermarket unit. While there are sometimes slight differences in fit and finish, most single DIN aftermarket units are designed to be installed in an adjustable collar that facilitates installation in just about any single DIN slot.

Replacing a Single DIN Radio With Double DIN

Since double DIN head units are twice the height of single DIN head units, you can always go from double to single, but going the other way presents space issues.

If your vehicle had an OEM option for a factory CD player, or any other additional piece of single DIN car audio equipment, then you do have the space, but you might run into other issues.

Before you proceed, it's important to make sure that the additional slot is actually a slot, and that it's actually two inches tall. Some vehicles have dummy slots that look like they're designed to accept a device like a CD player, but it's all for show.

You may find that there is no removable cover, and even if you did cut it away, it may have been hiding a mess of wires or ducting that prevent the installation of a double DIN head unit.

Some vehicles that have storage pockets under the head units can also look like they may accept a double DIN replacement, while there simply isn't enough space. The actual height of the opening may fit 1.5 DIN unit, or it may even be too small for that.

Dash Space and Other Difficulties

Assuming your dash has the space, the next problem you’ll run into is wiring. Even if you’re trying to replace a factory single DIN head unit with a factory double DIN head unit, you’ll typically find that the wiring harness connectors aren’t the same. That means you’ll either have to find an adapter or use a wiring diagram to splice a new connector into your existing wiring harness.

The next issue you may encounter is that even if your dash has a blank slot underneath the head unit, these “blank slots” are typically molded right into the dash instead of being a removable cap like you find in computer cases that have empty device bays.

And even if it does have a removable cap, and there's plenty of void space behind, it’s still probably just designed to allow you to slide in another single DIN device like a CD player. If you want to actually replace your single DIN head unit with a double DIN device, you'll most likely end up cutting out the part of the dash that separates the two slots.

If your vehicle had OEM option for a double DIN head unit, then you may be able to replace your existing dash or center console bezel with one that’s designed for a double DIN head unit. This isn’t always an option, but it is worth checking out.

Why Double DIN?

Before you go through all the work to replace your 1 DIN radio with a 2 DIN head unit, it might be worth asking yourself why you’re doing it.

Although double DIN head units have a lot more real estate for features like touchscreens and internal space for features like more powerful amps and built-in CD changers, that doesn’t necessarily make them better.

If you’re looking for a big touchscreen, you can find single DIN head units with slide-out screens that are pretty big. You can also add components like an external amplifier or a CD changer without cutting into your dash bezel, and you may even be able to use that additional single DIN slot for a graphic equalizer or another useful audio component.