SMS Segment and Cost Checker

Because a single GSM-encoded SMS holds 160 characters. Go one over and the message is split, and each part carries header data, so the limit drops to 153 characters per part rather than 160.

Characters outside the basic GSM set, including emoji, curly quotes and most accented letters, force the whole message into Unicode encoding. That cuts the limit from 160 characters to 70, so a short message with one emoji can cost three times as much to send.

Curly apostrophes pasted from a word processor are the usual culprit, because they look identical to a straight apostrophe and silently switch the whole message to Unicode. The euro sign, em dashes and ellipsis characters do the same.