It depends what is the character and what encoding it is in: 1  An ASCII character in 8-bit ASCII encoding is 8 bits (1 byte), though it can fit in 7 bits. 2  An ISO-8895-1 character in ISO-8859-1 encoding is 8 bits (1 byte). 3  A Unicode character in UTF-8 encoding is between 8 bits (1 byte) and 32 bits (4 bytes).