SMS Length Calculator

GSM-7 Basic Character Set

GSM-7 Extension Character Set (countes as two characters)

Emojis examples (partial list)

Unicode characters examples

How to Use the SMS Length Calculator

The SMS character counter is a free useful tool that can provide insights about a text message, such as the number of characters, encoding of characters used, estimate SMS message cost and more. How to use the character counter to find how many characters are in a text message:

• Step 1: Copy & paste or write your text message in the box above.
• Step 2: Check the detailed character breakdown for: Unicode characters, emojis (highlighted in red), GSM-7 extension characters that are counted as two characters (highlited in yellow).
• Step 3: Replace or remove discovered non-GSM characters in order to reduce SMS character length and the overall cost of the SMS.

You can also use the Unicode to GSM character converter tool for automatic replacement of non-GSM characters.

Basic and Extended GSM Alphabets

The basic GSM 03.38 alphabet uses 7 bits per character, comprising in total of 128 different characters with hexadecimal values from 0x00 to 0x7F.

There is also an extension of the GSM alphabet that defines an additional 10 characters along with the original 128. These characters are sent as two 7-bit encoded characters, starting with the 7-bit encoded escape character (0x1B) from the standard alphabet, followed by the extended caracter. That is why the characters within the extended GSM alphabet are counted as two characters.

What is GSM-7 and UCS-2 Encoding?

SMS messages can be encoded with either GSM-7 or UCS-2 character encoding. English alphabet, numbers, some latin and greek characters are all supported by GSM-7 encoding. You can check the full list of GSM-7 supported characters.

SMS messages that contain international languages or characters such as emojis, are sent using UCS-2 encoding.

The maximum number of characters that can be sent to network carriers per SMS message part is shown in the table below:

What is the SMS character limit and what is a message part?

SMS messages are measured in character chunks called parts (or segments) by all phone carriers throughout the world. Also, the sent SMS is billed per message parts. When you send an SMS message you need to be careful with the complete length of text message, because it will affect the number of parts (segments) of the message and the overall cost of sending.

That's why it is important to calculate the SMS character length in order to reduce costs of sending an SMS.
A single SMS message has a character restriction of 160 characters when sent using GSM-7 encoding and 70 characters when sent using UCS-2 encoding. Most current phones and networks, on the other hand, offer message segmentation, concatenation, and reconstruction of messages up to 1600 characters.

An SMS message that is longer than 160 GSM-7 characters or 70 UCS-2 characters will be split into multiple SMS parts. SMS Connexion needs six bytes in every message part for the User Data Header (UDH) in order to reassemble the message, to tell the handset the number of message parts that make up the concatenated SMS and the position of each message part within it.
This leaves only 153 GSM-7 characters or 67 UCS-2 characters in each message part, for long concatenated SMS. When the mobile phone has received all of the message parts, it shows them to the recipient as a single SMS.
In the table below is shown the maximum number of SMS characters in both encodings:

What type of encoding will my text message use?

When you send SMS texts with SMS Connexion, we employ the smallest possible encoding. Your communications will be encoded in GSM-7 if you exclusively use GSM-7 characters. If any characters other than GSM-7 are included in your message, it will be encoded in UCS-2, which limits each message segment to 70 characters.

See other tools:

• Validate single phone number - check if a number is a valid mobile phone
• Bulk phone number list validator - process a list of contact and validate, clean (remove invalid, duplicates), convert to E.164 format and estimate cost of sending an SMS
• Unicode to GSM converter - check text and replace non-GSM (Unicode) characters. Option to convert all Unicode characters detected or only specific languages: cyrillic, arabic, spanish, portuguese, etc.

References:

• Wikipedia - GSM 03.38 Default Alphabet
• Wikipedia - List of Unicode characters
• Unicode Character Code Charts

Privacy Note

This online tool does not store any information about you and it does not store any of the text that is written or pasted into the box above.