Each SMS can at most have 160 characters. Messages with more characters are sent as several message parts. There can be at most 9 message parts, totalling 1377 characters. Each message part is counted as one SMS in our statistics.
When using placeholders like Name, Surname, E-mail, etc, we are unable to calculate the message length, because the name of two receivers may be different. If you send a message to a group with 2 receivers, Ola and Kari, then the messagecount would differ depending on the receiver. This means that you should take into account different lengths of names etc when sending a message.
Character count is also dependent on what characters you use. When using normal characters, a message is sent as GSM-7, and you can have 160 characters per message. When a message contains special unicode characters, the character count is limited to 70 characters per message part. For a complete list of characters supported by GSM-7, you can read more here: https://en.wikipedia.org/wiki/GSM_03.38