How much disk space do you need to install Joomla!?
From Joomla! Documentation
Revision as of 14:47, 1 September 2012 by JoomlaWikiBot
15 megabytes (mb) of disk space should be enough for a default installation without additional extensions or media (such as image, audio, or video files). The database will be small when starting, and will grow when adding more content.