Determine Kernal bit 32 or 64 for Mac

Configurations

Open Terminal

$ uname -a

Darwin ryh.princeton.epam.com 15.4.0 Darwin Kernel Version 15.4.0: Fri Feb 26 22:08:05 PST 2016; root:xnu-3248.40.184~3/RELEASE_X86_64 x86_64

if i386, you have 32 bit
if x86_64, you have 64 bit