【How-to】What aspect ratio is 3840x2160

A 4K TV simply boosts that pixel count: Usually, 4K refers to a display resolution of 2160p, or 3,840 x 2,160 pixels. That’s roughly four times larger than a 1080p picture, hence the term “4K.” (Technically, 4K isn’t the same as 2160p, but the technical differences are so minor that it doesn’t really matter.)