The below table shows the storage sizes of the different data types in SQL Server.
| date | 3 bytes |
| datetime | 8 bytes |
| datetime2 | 6 – 8 bytes (depending on precision) |
| datetimeoffset | 10 bytes |
| smalldatetime | 4 bytes |
| time | 5 bytes |
| decimal | 5 – 17 bytes |
| numeric | 5 – 17 bytes |
| float | 4 or 8 bytes |
| real | 4 bytes |
| bigint | 8 bytes |
| int | 4 bytes |
| smallint | 2 bytes |
| tinyint | 1 byte |
| money | 8 bytes |
| smallmoney | 4 bytes |
| char | size defined in table |
| varchar | 2 bytes + data size |
| text | data size |
| nchar | 2 times size defined in table |
| nvarchar | 2 bytes + 2 times data size |
| ntext | 2 times data size |
| binary | size defined in table |
| varbinary | 2 bytes + data size |
| image | 2 bytes + data size |
| bit | 1 byte |
| hierarchyid | 5 bytes |
| uniqueidentifier | 16 bytes |
Reference: http://msdn.microsoft.com/en-us/library/ff848794.aspx
Thanks!