Why is an int typically 4 bytes in C and C++?

Hello Jay, really nice question.

An int didn’t become 4 bytes by magic — it’s mostly about how modern computers are built. Today’s systems are designed around 32-bit or 64-bit architectures, and a 4-byte (32-bit) integer lines up nicely with how the CPU reads and processes data.

Here’s the idea in simple terms:

1. Efficiency
   A 32-bit value fits naturally into the CPU’s data pathway, so the processor can read, write, and do math on it quickly.

2. Standard practice
   Over time, most platforms settled on 4 bytes for int because it balances speed and memory use. It became the “common size” on modern systems.

3. Range of values
   With 4 bytes, you can represent over four billion different values, which is enough for most everyday programming tasks.

If you run:

cout << sizeof(int);

and see 4, that’s your system telling you the natural size it uses.

If you have further questions, I'm here to help.