Varchar2 vs Nvarchar

Oracle AL16UTF16:

Varchar2(N char) == Nvarchar(N) in SQL Server

Varchar2(N) == Nvarchar(2*N) in SQL Server

Oracle AL32UTF8:

Varchar2(N char) == Nvarchar(3*N) in SQL Server

Varchar2(N) == Nvarchar(3*2*N) in SQL Server

https://forums.oracle.com/forums/thread.jspa?threadID=709453&tstart=98&messageID=2788167

Chinses character always takes up two characters.