Because the game was designed for consoles, its "size" on PC depends entirely on the version you are using:
Plan for at least 10 GB to account for the game file and shader caches. I played WWE 2k13 on Xbox 360 earlier today. - Facebook wwe 2k13 pc size
For comparison, the Xbox 360 version of WWE 2K13 required only 6.5 GB of hard drive space when fully installed. The PC port, while largely identical in visuals, included higher-resolution texture options and anti-aliasing settings that bloated the file size slightly. It also lacked any form of physical disc release—Steam was the only option—meaning every megabyte had to be downloaded. In an era when 8 GB could take three to six hours over a standard 5 Mbps broadband connection, the size was a genuine hurdle for rural players. Because the game was designed for consoles, its