How to Test the Length of an SMS Message

1. Testing the length of an SMS message is a straightforward task. You need to calculate how many characters your SMS message can contain. Depending on what language you are writing it in, you can write a message containing the maximum amount of characters or fewer.
2. Decide what language to use to send your SMS message. The character set your type in affects the maximum allowed length of your message. In compliance with GSMA standards, all SMS messages can contain up to 1120 bits of data, but some characters use more bits than others. The sum of all the characters in your message must be 1120 bits or less.
3. Using English, or a standard Latin character subset, means you will be using the regular 26 letters of the Latin alphabet plus associated numbers and basic punctuation. Each character in the standard Latin alphabet is seven bits. This means you will be able to send up to 160 characters in your message, including punctuation.
4. Using diacritical marks, like accents common in Dutch, French, Spanish and German, means the use of additional data bits. Each of the characters contained in this character set use eight bits of data. Therefore, an SMS message in that character set can be a maximum of 140 characters long.
5. Writing a message in a non-Latin character set, such as Arabic, Korean or Chinese, involves a different character set. Because of the complexity of these characters, each one is 16 bits in size. This limits SMS messages to a maximum of 70 characters in length.
6. Once you have worked out the permitted length of your SMS message, test the length of the message you intend to send by counting out the number of characters in contains, including spaces. If your message exceeds the permitted number of characters, you must shorten it in order to send it correctly.