Selecting the Right GPS Screen Size

Bigger is better unless the windshield view is blocked

Automobile's GPS Navigation System
Andrew Fox/Getty Images

The screens on dedicated car GPS devices originally came in two diagonal sizes: 3.5 inches and 4.3 inches. Thanks in part to competition from smartphones and the desire on the part of GPS makers to differentiate their products in an increasingly competitive market, larger screens are much more common now. Screens in the 5-inch size used to be rarities, but now all the big manufacturers have at least a few 5-inch models. Some manufacturers, such as Magellan, have ventured into behemoth screen territory with 7-inch screens.

Choosing a GPS Screen Size

While there are still 3.5-inch screen size GPS models on the market, you can find 4.3-inch models for barely a few dollars more across the performance and features spectrum. That precious bit of extra screen real estate makes a significant difference in visibility and ease of use of touch-screen controls. With all the available screen sizes, it is hard to recommend a 3.5-inch screen size GPS to anyone for any purpose.

Screens in the 4.3-inch and the 4.7-inch size are fine for the majority of users. The extra real estate provided by larger screens is nice, but not essential for most purposes. As manufacturers improve screen resolution, as Garmin and TomTom have done with their new glass capacitive touch-screen models, you get a much sharper, clearer image in the 4.3-inch and 4.7-inch screen size format.

Bigger Is Usually Better

Visibility improves as size increases, and touch screens are easier to use on larger screens. The 5-inch screen is the preferred size for car GPS devices for all except vehicles with small windshields, where the larger GPS might block the view of the road.

Large vehicles, such as RVs and trucks, usually have windshields that are farther away from the driver than in passenger cars. Also, trucks and RVs usually have larger windshields overall, permitting the use of larger GPS devices without blocking your view of the road. A big-screen 6-inch or 7-inch screen GPS is easier to see in large cabs. Some GPS makers offer large-screen, trucker and RV-specific models, such as the 7-inch screen Garmin Dezl. In addition to its large screen, the Dezl has a speaker capable of louder-than-typical volumes, and a number of big-rig specific routing features.

If you're still not sure which GPS screen size is right for you, stop by an electronics retailer—you may want to call first to find out which units are on display—and compare screen sizes in the store.