The important thing is the core factor.
See the table in the following url to calculate your license needs ->
http://www.oracle.com/us/corporate/contracts/processor-core-factor-table-070634.pdfIntel's core factor is 0,5
Core factor for SPARC M5, SPARC M6, SPARC M7, SPARC M8 is also 0,5
See the url above for the details.
Basically if you have 1 physical cpu with 16 core and if your CPU is intel, then you wiill need to have 6 cpu license.
For cpu based license, the general formula is ;
servers * sockets per servers * cores per socket * core factor