3840 x 2160 is a resolution commonly referred to as 4K UHD (Ultra High Definition) . It has a total of about 8.3 million pixels, with 3840 pixels horizontally and 2160 pixels vertically. This resolution is exactly four times the pixel count of Full HD displays (1920 x 1080 pixels) . It is also sometimes referred to as 2160p, based on the naming patterns established by the previous 720p and 1080p HDTV standards. The aspect ratio of 3840 x 2160 is 16:9.