5 1/4 inches x 7 1/2 inches.
Description from Entertainment Earth:
Whose side will you be on in the battle for the galaxy? Show your support for Boba Fett and the Mandalorians with this Star Wars Mandalorian Skull Window Decal! The decal measures approximately 5 1/4-inches x 7 1/2-inches.
UV and water resistant, FanWraps window decals are made of a clear poly window film, printed in full color to produce eye popping visuals. Safe to use on any home or auto window surface, they feature DIY installation, automotive-grade materials, and clean removability. Window use only.