Double DIN is a size standard for car stereos. It refers to a head unit that measures 4 inches (100 mm) tall and 7 inches (180 mm) wide. “DIN” stands for Deutsches Institut für Normung, the German standards organization that originally defined the universal car radio slot size. A standard, or “single,” DIN opening is 2 inches tall. Double DIN is simply twice that height at the same width.
Where the DIN Standard Came From
In the 1980s, the German-defined radio slot became the global standard for car audio. Every major automaker adopted it so that aftermarket stereos could fit across different makes and models without custom fabrication. The single DIN slot, at 2 inches by 7 inches, became the baseline. Double DIN doubled the vertical space to 4 inches, giving manufacturers room for larger displays and more controls.
There’s also a less common 1.5 DIN size, measuring 3 inches tall by roughly 8 inches wide. American automakers used this in many vehicles starting in the mid-1970s, but it never caught on as a universal standard. Today, virtually all car stereos are built to either single or double DIN dimensions.
Single DIN vs. Double DIN
Both sizes are 7 inches wide and handle the same basic audio functions: power, volume, source selection, and sound controls. The difference is what you can do with the extra vertical space. Double DIN units have room for larger, more readable buttons and, more importantly, touchscreens. Most touchscreen head units are double DIN because a 2-inch-tall display simply isn’t practical for navigation maps, album art, or phone interfaces.
A double DIN touchscreen typically starts at 6.2 inches measured diagonally, with many models offering 7-inch screens. That’s enough real estate for Apple CarPlay, Android Auto, GPS navigation, and a live rear-view camera feed. Single DIN stereos can still offer Bluetooth and basic phone connectivity, but the experience is limited to small text displays or physical buttons.
One newer option blurs the line: floating-screen stereos use a single DIN chassis but mount a large touchscreen (sometimes 9 or 10 inches) that extends above the dash opening. These give you a big display without needing a double DIN slot, though the screen does protrude from the dashboard surface.
How to Check Your Car’s DIN Size
The simplest way to find out whether your car has a single or double DIN opening is to measure the stereo slot in your dashboard. If the opening is roughly 2 inches tall, it’s single DIN. If it’s about 4 inches tall, it’s double DIN. Some vehicles come with trim panels or storage pockets that can be removed to reveal a larger opening underneath, so the factory look can be deceiving.
For a more reliable answer, check the Metra Vehicle Fit Guide online. Metra is the largest manufacturer of car audio installation parts, and their database covers nearly every vehicle. When you search your car’s year, make, and model, you’ll see available dash kits listed by model number. A kit starting with “99-” means your car accepts single DIN. A kit starting with “95-” means it accepts double DIN. If both numbers appear, your dashboard can accommodate either size with the appropriate kit.
What a Dash Kit Does
Car dashboards aren’t all shaped the same on the outside, even though the stereo openings follow DIN standards. A dash kit is a plastic or metal frame that bridges the gap between your vehicle’s specific dashboard contour and the flat rectangular shape of an aftermarket stereo. It snaps or screws into the factory opening and gives the new head unit a clean, flush appearance.
If you’re converting from a single DIN opening to a double DIN unit (in vehicles where the space behind the dash allows it), the dash kit also fills in any gaps left by the taller stereo. Some kits include extra storage pockets or trim pieces for a factory-finished look. You’ll also need a wiring harness adapter that connects your car’s electrical plugs to the stereo’s connectors, so no cutting or splicing is required.
Features in Modern Double DIN Units
The main reason people upgrade to a double DIN stereo is the touchscreen and the smartphone integration that comes with it. Most current models support wireless or wired Apple CarPlay and Android Auto, which mirror your phone’s navigation, music, messaging, and calling apps directly on the car’s display. You interact with them through the touchscreen or voice commands, keeping your phone in your pocket.
Beyond phone integration, double DIN head units commonly include Bluetooth audio streaming, USB and SD card playback, customizable equalizer settings, and one or more camera inputs. A rear-view camera input is especially popular since it turns the stereo screen into a backup display whenever you shift into reverse. Some higher-end models add multiple camera angles, built-in GPS navigation that works without a phone signal, and capacitive touchscreens that respond to swipe gestures like a tablet.
Screen sizes on floating-display double DIN models now reach 10 inches or larger, offering better visibility for maps and sharper video quality overall. Even standard in-dash models with 7-inch screens provide a significant upgrade over a basic single DIN radio, particularly for drivers who rely on their phone for directions or hands-free calls.