SELECT table_schema AS 'Database', ROUND(SUM(data_length + index_length) / 1024 / 1024, 2) AS 'Size (MB)' FROM information_schema.TABLES GROUP BY table_schema ORDER BY 2 desc
This simple SQL query will return the size of all databases of your MySQL Server, listing the largest databases first. This can be useful when figuring out which databases take up most of the space and must be moved to another server. You can execute this query using phpMyAdmin, Navicat, HeidiSQL, or similar software. It may take a bit of time to return the results.
Here is a sample query and its results: