Video resolutions, from 240p to 4K

The numbers

A resolution is just how many pixels make up each frame. The number people quote is the height, so 1080p means 1080 rows of pixels from top to bottom, and 1920 across for a normal widescreen frame.

• 240p, 426 x 240, about 0.1 megapixels
• 360p, 640 x 360, about 0.23 megapixels
• 480p, 854 x 480, about 0.4 megapixels
• 720p, 1280 x 720, about 0.9 megapixels, often called HD
• 1080p, 1920 x 1080, about 2 megapixels, Full HD
• 1440p, 2560 x 1440, about 3.7 megapixels, often called 2K
• 2160p, 3840 x 2160, about 8.3 megapixels, called 4K

Each step up roughly doubles the pixel count. 4K is four times 1080p, not twice, which is why the file sizes climb the way they do.

Which one does a viewer actually need

Less than you think, most of the time. On a phone held at arm's length, most people cannot reliably tell 720p from 1080p. On a laptop, 1080p is comfortably enough. The difference between 1080p and 4K only becomes obvious on a large television, or when someone is close to a big monitor.

That does not make the high rungs pointless. It makes them situational, which is exactly why you keep several and let the player choose.

What each one costs you

Storage follows pixels and motion. On our encoder, one hour of video costs roughly 0.2 GB at 240p, 1 GB at 720p, 2 GB at 1080p and 7 GB at 4K. A full set of every quality for one hour of 1080p source works out around 3.6 GB, measured across 551 hours of real uploads.

If your storage is filling up, the first thing to check is whether you actually need the top rung on every video. A screen recording of a slide deck does not gain much at 4K.

One thing that catches people out

We never upscale. If you upload a 720p file, you get 720p and below, not a fake 1080p version. Upscaling adds pixels without adding detail: bigger file, same picture. Your top rung is whatever you gave us.