2 ms·HD ~= 1080p ~= 1K. 4 x 1080p ~= 4K.by chrischen 5y agoHD ~= 1080p ~= 1K. 4 x 1080p ~= 4K.edgyquant 5y agoBut 4K isn’t 4x 1080 (as a description of height) it is 2xchrischen 5y agoYes they went from counting interlaced vertical lines to progressive lines, to the number of 1080P pixels. The 4 in 4K refers to the number increase in pixel count.