SharePoint Site Template Size

Posted on November 28, 2009 Updated on May 20, 2015

When you turn an existing site into a template and include the content, there is a size limit of 10 Mb by default. If you site content is greater than this, a site template will not be created.
You can change this maximum size using an stsadm command on the SharePoint server.

stsadm -o setproperty -propertyname max-template-document-size -propertyvalue  size_in_bytes
 
Where size can be up to 500Mb (524288000 bytes)