My .enc file is now >13.5 GB and growing rapidly -- mostly because of all the crap that other EMR's send us, that we feel obliged to file in the patients' charts. The actual AC database file is probably about 1.5G
The actual database itself is quite small for the average physician. Most are below 200 MB in size for a solo practice. If your SQL database file is greater than 1-2GB as a solo provider, you could have a build up log files in your database. Check the size of the MDF/LDF files in your AC folder.