What is a Byte?

The byte equals 8 bits and is the smallest addressable storage unit in modern computing and digital systems. Byte-sized addresses are universal in computer architectures from microcontrollers to supercomputers, making the byte the fundamental block of memory and storage. A single ASCII character is 1 byte (256 possible values), basic UTF-8 characters use 1–4 bytes, and a UTF-16 character uses 2 bytes. File sizes, RAM capacity, and disk space are all measured in bytes and their multiples. The byte relates to the bit (1 byte = 8 bits), the kilobyte (1,000 or 1,024 bytes — see decimal vs. binary), the kibibyte (1,024 bytes, the strict computing standard), and larger multiples (MB, GB, TB). Note: storage manufacturers use decimal (1 GB = 10⁹ bytes), while operating systems often use binary (1 GiB = 2³⁰ bytes), causing the famous discrepancy where a '1 TB drive' shows about 931 GB free.

Visual reference for how the byte relates to other data units. Each row links to the full converter for that pair.

• File sizes everywhere (documents, images, video)
• RAM and storage capacity
• Character encoding in programming

• ✓1 byte = 8 bits.
• ✓KB, MB, GB are 1000 or 1024 multiples of bytes — check context.
• ✓Use bytes (B) for storage; bits (b) for bandwidth.

• ✗Confusing byte (B) with bit (b).
• ✗Assuming 1 MB always equals 1,048,576 bytes — sometimes 1,000,000.
• ✗Mixing file size (bytes) with transfer speed (bits per second).