Continuing in a tradition the iPhone SE and iPhone 6s line started, Apple’s newest iPhones 8 and iPhone X can shoot 4K video, too. Essentially 2160p, that’s four times as many pixels — twice horizontal and twice vertical — as 1080p. And with iOS 11 shipping alongside the new iPhone, that video will take up roughly half as much space, thanks to the new HEVC codec being employed.
How much storage space will the iPhone X’s 4K video take up? | iMore