Basically, one rack unit measures 44.45 mm or 1.75 inches in height. This unit is also known as “1U”. Most server cabinets are available in 48U, 44U, 42U, and 40U enclosures. If you want to measure the internal space, you can multiply the number of units by 1.75. Let’s take an example. Your 44U enclosure provides 77 inches of internal space. Let’s suppose you want to include 20 2U units to the data center. In this case, you may want to opt for a 44U cabinet as this will provide plenty of space. Based on these measurements, you can purchase as many units as you need. It all boils down to your needs and budget.
If you want to get a better idea of the dimensions that will fit your available space, you may want to find out the type of equipment that you want to install in the cabinets. Here is an important tip: you may want to get a few more cabinets for future expansions. Basically, it’s better to add at least 10% additional space as you won’t be able to adjust the rack units once you have purchased your server cabinets. Aside from this, it’s important to keep in mind that the units should fit through stairways and doorways. Moreover, they should meet other clearance regulations of the facility they are going to be installed in.