32-bit

N-bit Processors
4-bit 8-bit 16-bit 24-bit 31-bit 32-bit 48-bit 64-bit 128-bit
N-bit Applications
    16-bit   31-bit 32-bit   64-bit  
N-bit Data Sizes
4-bit 8-bit 16-bit     32-bit   64-bit 128-bit
nibble byte octet word dword qword
These definitions are relevant to the world of x86 processors. See linked articles for discussion of the meaning in other architectures. The 31-bit and 48-bit sizes relate to IBM mainframes and AS/400s, respectively.

In computer architecture, 32-bit is an adjective used to describe integers, memory addresses or other data units that are at most 32 bits (4 octets) wide, or to describe CPU and ALU architectures based on registers, address buses, or data buses of that size. 32-bit is also a term given to a generation of computers, during which time 32-bit processors were the norm.

The range of integer values that can be stored in 32 bits is 0 through 4294967295, or -2147483648 through 2147483647 using two's complement encoding. Hence, a processor with 32-bit memory addresses can directly access 4 GiB of byte-addressable memory.

The external address and data buses are often wider than 32 bits but both of these are stored and manipulated internally in the processor as 32-bit quantities. For example, the Pentium Pro processor is a 32-bit machine, but the external address bus is 36 bits wide, and the external data bus is 64 bits wide.

See also

de:32-Bit-Architektur it:32 bit nl:32 bit pl:Architektura 32-bitowa zh:32位元