marketing... 1920 x 1080 - 1080p usually 2560 x 1440 - 1440p usually 3840 x 2160 - 4k usually They used the right side for the first two or 1080p/1440p then switched to the left side. left side is 3840 or roughly 4,000 which would be 4k 3840 rounded up is 4,000 or could be represented as 4k. ----- lay this out... 1920 x 1080 2560 x 1440 3840 x 2160 ----- using the left side - "k" referring to thousand so 1,000 is 1k and 5,000 is 5k. 1920 or 2k (rounded up) 2560 or 2.5k (rounded down) 3840 or 4k (rounded up) ----- using the right side 1080 or 1080p 1440 or 1440p 2160 or 2160p ----- Marketing used 1080p / 1440p then switched to the left side (over night basically) and started calling it 4k. Basically what I'm doing is dropping 1080p, 1440p, and/or 2160p. This is gone. Left side is usually represented in the thousands, but a "k" is used instead. So 2k, 2.5k, and/or 4k. Now what I did to just be a villian. I switched to the right where it was 1080p / 1440p / 2160p. I switched to doing it by the thousand. So the right would be done in "k". It then becomes 1k (1080p) / 1.5k (1440p) / 2k (2160p). ----- I also flipped it in the post from either side. ----- reality though either side could be "k" though since that's just 1,000. 1920 x 1080 ||||| 1.92k x 1.08k ||||| 2k x 1k - rounded 2560 x 1440 ||||| 2.56k x 1.44k ||||| 2.5k x 1.5k - rounded 3840 x 2160 ||||| 3.84k x 2.16k ||||| 4k x 2k - rounded ----- 3840 x 2160 - not "true 4k" - using the left side - 3840 is under 4,000 5120 x 2880 - "true 5k" - using the left side - 5120 is over 5,000 (truly over 5k or is "true 5k".