The other night I searched for the measurements of a 1U server. "How big is a 1U server" or "what are the dimensions of a 1U server" queries returned a lot of links to purchase servers, yet few gave the answer I sought. Finally, I located this 1U Rack Mount Case drawing | local copy. Useful info when you're trying to determine how many U that old 486 desktop will take in the rack. A little quick math: