title: Get overall sum of all databases size in a SQL Server
body: <p>I want to calculate how much space my databases are using in a server. I could use <code>sp_spacefiles</code> or query <code>sys.databases</code> table but that would give me separate results for each database and I would have to copy that into an excel sheet and calculate the sum from there.</p>
  
  <p>Is there a direct way of doing it in T-SQL?</p>
  
  <p>Thanks.</p>