An IP address is 32 bits long.

 A byte is a unit of information that consists of eight bits. A bit is a binary digit that can have a value of either 0 or 1. An IP address is 32 bits long, which means it is composed of four groups of eight bits each. Therefore, if converted to bytes, an IP address would be four bytes long. For example, the IP address 192.168.1.1 in binary form is:

11000000.10101000.00000001.00000001

This IP address has four groups of eight bits each, which are equivalent to four bytes. References: CompTIA IT Fundamentals+ Study Guide: Exam FC0-U61, Second Edition, Chapter 6: Infrastructure Concepts, page 221.