When composing your SMS, there are 2 types of characters you can use:
Standard characters – those from the GSM Basic Character Set (see below)
Unicode characters –characters that aren’t in the GSM 03.38 basic character set, including emojis.
According to carriers, 1 standard SMS message has a maximum of 160 characters. You do not have to limit yourself to sending 160 characters,
Tip: No matter how many message parts, your SMS will always be delivered as 1 long message to the recipient. It will NOT be split or delivered separately.
When a message is longer than 160 characters, this is referred to as a multi-part message. The total SMS limit then becomes 153 characters per ‘part’ as the 7 characters are used up by invisible headers and footers which denote which part of the message is being sent (i.e. Part 1 of 2). For example: If a message is
longer than 6 message parts, it will be truncated (see below).
GSM Basic Character Set:
1 – 160 characters = 1 Message
161 – 306 characters = 2 Messages
307 – 459 characters = 3 Messages
460 – 612 characters = 4 Messages
613 – 765 characters = 5 Messages
766 – 918 characters = 6 Messages
919 – 1071 characters = 7 Messages
1072 – 1224 characters = 8 Messages
Non-GSM (Unicode) characters:
1 – 70 characters = 1 Message
71 – 134 characters = 2 Messages
135 – 201 characters = 3 Messages
202 – 268 characters = 4 Messages
269 – 335 characters = 5 Messages
336 – 402 characters = 6 Messages
403 – 469 characters = 7 Messages
470 – 536 characters = 8 Messages