HELM determines your disk space by adding all web data, emails currently on the server for your domain, as well as the size of all databases hosted under your domain. To determine the amount of disk space you are using, log into HELM control panel and navigate to your sites "Statistics"

This will provide a breakdown of your Web disk space usage, as well as your Email disk space usage. Please note, however, that your TOTAL disk space usage also includes the size of your data base, which is not displayed here.