Size in dp (WxH)	Description	Availability	AdSize constant
320x50	Banner	Phones and Tablets	BANNER
320x100	Large Banner	Phones and Tablets	LARGE_BANNER
300x250	IAB Medium Rectangle	Phones and Tablets	MEDIUM_RECTANGLE
468x60	IAB Full-Size Banner	Tablets	FULL_BANNER
728x90	IAB Leaderboard	Tablets	LEADERBOARD
Screen width x 32|50|90	Smart Banner	Phones and Tablets	SMART_BANNER

 

< com.google.android.gms.ads.AdView
            xmlns:ads="http://schemas.android.com/apk/res-auto"
            android:id="@+id/adView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:layout_alignParentBottom="true"
            ads:adSize="BANNER"
            ads:adUnitId="ca-app-pub-3940256099942544/6300978111">