💾 Byte Calculator
Enter any text to instantly see its byte size in UTF-8, UTF-16, and other common encodings.
UTF-8 Bytes
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B
UTF-16 Bytes
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B
ASCII Bytes
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B
Characters
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chars
Size (KB)
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KB
Non-ASCII Chars
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chars
Encoding reference:
• ASCII (a–z, 0–9, etc.): 1 byte in UTF-8 and ASCII
• Latin/European chars: 2 bytes in UTF-8
• CJK (Chinese, Japanese, Korean): 3 bytes in UTF-8
• Emoji: 4 bytes in UTF-8
• ASCII (a–z, 0–9, etc.): 1 byte in UTF-8 and ASCII
• Latin/European chars: 2 bytes in UTF-8
• CJK (Chinese, Japanese, Korean): 3 bytes in UTF-8
• Emoji: 4 bytes in UTF-8
❓ FAQ
A byte is a unit of digital information consisting of 8 bits. It is the basic unit of text storage in computers. A single ASCII character (letter, digit) occupies exactly 1 byte.
UTF-8 is a variable-length encoding. It uses 1 byte for ASCII characters (code points U+0000–U+007F), 2 bytes for most European characters, 3 bytes for CJK characters, and 4 bytes for emoji and supplementary characters.
Byte count is critical for database VARCHAR column sizes, HTTP header limits (8KB per header typically), cookie size limits (4KB), and API payload restrictions. Many systems measure strings in bytes, not character count.
1 KB (kibibyte) = 1,024 bytes. In SI units, 1 kB (kilobyte) = 1,000 bytes. Most operating systems and programming contexts use 1 KB = 1,024 bytes.
UTF-8 uses 1–4 bytes per character and is the web standard. UTF-16 uses 2–4 bytes per character and is used internally by JavaScript, Java, and Windows APIs. For ASCII-heavy text, UTF-8 is more compact. For CJK-heavy text, the sizes are similar.