AdMob Ad Sizes

This article briefly covers the different advertisement (ad) sizes for moblie Apps provided by AdMob. The list of sizes is in the table at the end of the article. If you want some more background read on.

Google sells advertising through two large channels: the AdSense platform for ads displayed on websites; and the AdMob service, for ads displayed in Apps. AdMob serves billions of ads to many millions of Android, Windows Phone, iPhone and iPad users. Alongside paid for Apps and in App billing the displaying of ads is a monetization method for App developers. For the Android platform Google's AdMob is built into the Google Play Services SDK.

There is a wide variety of screen sizes and screen densities on the many types of mobile devices in use today. Therefore the ads come in various sizes as well. The data in this article has been generated from the information published in the Google AdMob development guide.

What is the Device-Independent Pixel or DP?

In the AdMob Ad Sizes table at the end of the article the ads are ordered by the total number of pixels in the ad unit, i.e. by how much space the ad takes up. It is calculated by multipling the width of the ad by its height. Ad sizes are based upon a device-independent pixel (dp) and not a devices physical screen pixel. This is because the pixel density of screens varies dramatically. For example a Samsung Galaxy S7 has approximately 577 pixels per inch (PPI), compared to a Samsung Galaxy Ace at around 165 PPI. Therefore a one inch by one inch image on the Ace needs to be 165x165 pixels. On the S7 it needs to be 577x577 pixels.

Apps will provide the same image at different densities to support a range of screens. The Android Operating System (OS) defines a baseline medium density display at 160 dots per inch (DPI). At this baseline one physical pixel equals one device-independent pixel. From this base line all image assets are scaled (if not provided). Thus ads may be scaled up or down to suit higher or lower screen densities. This is done automatically by the Admob code:

• Low Density Screens, around 120 DPI, scaling factor 0.75, e.g. 320×50 becomes 240×37.
• Medium Density Screens, around 160 DPI, no scaling, e.g. 320×50 stays at 320×50.
• High Density Screens, around 240 DPI, scaling factor 1.5, e.g. 320×50 becomes 480×75.
• Extra High Density Screens, around 320 DPI, scaling factor 2, e.g. 320×50 becomes 640×100.
• Extra Extra High Density Screens, around 480 DPI, scaling factor 3, e.g. 320×50 becomes 960×150.

Ad Size Standards

There are guildeline sizes for ads. The Interactive Advertising Bureau (IAB) issues guidelines, as does the Mobile Marketing Association (MMA) with their guidelines. AdMob ads are sized to these guidelines or close to them. When adding ads to Apps most are displayed as banners, usually across the top or bottom of the screen, in both landscape and portrait mode. The ad unit type called Smart Banner helps with User Interface (UI) design. A Smart Banner ad will determine the screen area available for the ad, based on the screen width, and serve one at an appropriate size. This helps simplify the work needed to support the many types of screen sizes in use. Even with a Smart Banner the ad may not fill the entire width of the screen. In which case the add is center justified with a color fill on either side.

List of AdMob Ad Sizes

For more information see the relevant page for Android, iOS or Windows Phone in the AdMobs documentation. This includes the programming constant to use for each size in the API code.