What size data cabinet do I need?

To find out the size of cabinet you need, add the rack-height (in U) of all the equipment to be housed in the cabinet including patch panels, switches, UPS systems, PDUs and cable management. Rememmber to leave spare capacity for future expansion. It is also important to check the usuable depth of the cabinet as well as the overall rack height. The usable depth will be shorter than the overall depth, and should leave sufficient space for cable bends, patch lead connection and airflow.