32 or 64 bit Mac?

How to tell if you have a 32 or 64 bit Mac Choose About This Mac from the Apple () menu in the upper-left menu bar, then click More Info.
Open the Hardware section.
Locate the Processor Name.

Compare your Processor Name to information below to determine whether your Mac has a 32-bit or 64-bit processor.
Processor Name 32- or 64-bit
Intel Core Solo 32 bit
Intel Core Duo 32 bit
Intel Core 2 Duo 64 bit
Intel Quad-Core Xeon 64 bit
Dual-Core Intel Xeon 64 bit
Quad-Core Intel Xeon 64 bit
Core i3 64 bit
Core i5 64 bit
Core i7 64 bit