Database File Size and Free Space

USE [Database Name];

SELECT [name] AS [File Name]

      ,[physical_name] AS [Physical Name]

      ,[size]/128 AS [Total Size in MB]

      ,[size]/128.0 - CAST(FILEPROPERTY(name, 'SpaceUsed') AS int)/128.0 AS [Available Space In MB]

FROM sys.database_files;