Server Rack Buying Guide: Sizes, Rack Units and Accessories Explained
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A good rack keeps your network and server equipment organised, cool and secure. Before you buy, plan around these points.
Understand rack units (U)
Rack height is measured in rack units. One unit (1U) is 1.75 inches (44.45 mm). A 1U switch takes one unit, a 2U server takes two. Add up the height of everything you plan to install, then add around 25% spare space for future growth, patch panels and cable management.
Standard width: 19 inches
Almost all rack-mount network and server equipment is designed for the 19-inch standard, which refers to the width of the mounting rails.
Choose the right type
- Wall-mount racks — compact and ideal for small offices, comms rooms and patch panels.
- 2-post open frame — easy access for lightweight network gear such as switches and patch panels.
- 4-post open frame — supports deeper, heavier equipment like servers, with excellent airflow.
- Enclosed cabinets — lockable doors and side panels add security and help manage airflow and dust.
Check the depth
Servers can be much deeper than switches. Measure the depth of your deepest device and leave extra room at the back for power and network cables. Adjustable-depth racks give you more flexibility.
Essential accessories
- Shelves for non-rack-mount devices like routers, NAS units and mini PCs
- Blanking panels to close empty spaces and improve airflow
- Cable management bars and rings to keep patch cables tidy
- Rack-mount PDUs and UPS units for organised, protected power
- Cage nuts and screws for mounting equipment
Finally, check the rack's weight capacity and plan for ventilation — heat is one of the biggest causes of equipment failure.