In what unit is rack height measured?

Rack height is measured in "U" units, which stands for "rack units." One rack unit is typically defined as 1.75 inches in height. This unit of measurement is standard in the industry for specifying the height of server racks and other types of equipment that can be mounted in racks. Using "U" as a measurement allows for a consistent way to convey how many units tall a piece of equipment is, making it easier for technicians to know how much vertical space it will occupy in a given rack.

While inches, feet, and centimeters can also measure physical dimensions, they are not the standard when it comes to rack-mounted equipment. The use of "U" units creates a universal terminology that simplifies planning and installation of equipment into racks, ensuring compatibility and proper use of available space.