Confusing result in migrating VARCHAR2 from Oracle to MSSQL2014 VARCHAR

Hi Guys,

I am using SSMA for Oracle to migrate Oracle DB to MSSQL 2014.

However I am confused with the following result :-

Field01 varchar2(100) in Oracle is converted to varchar(400) in MSSQL which is 4 times its original size

Another field varchar2(2000) in Oracle is converted to varchar(4000) in MSQL which is only 2 times its original size

Some varchar2 fields maintains their size after migrating.

What the purpose of making the converted field size bigger and why is inconsistency ?

Please help.

Thank You