Hello there! We appreciate you checking out our Toto UT447E Cotton White Commercial Washout High Efficiency Urinal. The rough-in dimensions may either be 19 5/8" (500mm) or 12 5/8” (321mm), depending on the height you wish to set it at. This is of course the Urinal rough in, If you would like the rough in dimensions for the flush valve please let us know which flush valve you are looking to purchase and we would be happy to give you the information you desire. If you have not yet decided, we recommend the TEU1LA12#CP EcoPower High-Efficiency Urinal Flush Valve (as shown in the picture above). For more information, details, and guidelines on installation, feel free to view this Installation Manual. Should you have further questions, please let us know. We are eager to make online shopping as fast and easy for you! Thank you for choosing plumbersstock.com!