Maximum length for MySQL type text

See for maximum numbers:http://dev.mysql.com/doc/refman/5.0/en/storage-requirements.html

TINYBLOB, TINYTEXT       L + 1 bytes, where L < 2^8    (255 Bytes)BLOB, TEXT               L + 2 bytes, where L < 2^16   (64 Kilobytes)MEDIUMBLOB, MEDIUMTEXT   L + 3 bytes, where L < 2^24   (16 Megabytes)LONGBLOB, LONGTEXT       L + 4 bytes, where L < 2^32   (4 Gigabytes)

L is the number of bytes in your text field. So the maximum number of chars for text is 2¹⁶-1 (using single-byte characters). Means 65 535 chars(using single-byte characters).

UTF-8/MultiByte encoding: using MultiByte encoding each character might consume more than 1 byte of space. For UTF-8 space consumption is between 1 to 4 bytes per char.

TINYTEXT: 256 bytes
TEXT: 65,535 bytes
MEDIUMTEXT: 16,777,215 bytes
LONGTEXT: 4,294,967,295 bytes

Type       | Approx. Length     | Exact Max. Length Allowed-----------------------------------------------------------TINYTEXT   | 256 Bytes          |           255 charactersTEXT       |  64 Kilobytes      |        65,535 charactersMEDIUMTEXT |  16 Megabytes      |    16,777,215 charactersLONGTEXT   |   4 Gigabytes      | 4,294,967,295 characters

Basically, it's like:

"Exact Max. Length Allowed" = "Approx. Length" in bytes - 1

Note: If using multibyte characters (like Arabic, where each Arabic character takes 2 bytes), the column "Exact Max. Length Allowed" for TINYTEXT can hold be up to 127 Arabic characters (Note: space, dash, underscore, and other such characters, are 1-byte characters).