# SMS segment

> A segment is the unit an SMS is billed in: one 140-byte message part, holding 160 GSM-7 or 70 Unicode characters when alone, 153 or 67 when part of a longer concatenated message.

Carriers charge per part transmitted, not per message as the user sees it. A 300-character GSM-7 text is two segments (153 + 147), a 300-character Arabic text is five (67 each), and both appear as one message on the phone. The rate card is therefore always a price per segment.

The arithmetic is worth doing before a send: a 161-character message costs twice a 160-character one. Most transactional texts fit in one segment by design; marketing texts are the ones that creep.

At SMSMeteor: every rate on the [rate card](https://smsmeteor.com/pricing) is per segment; the API returns `segments` and `price` for each message, and campaigns are priced on the longest rendered row. Up to 6 parts per message.

Related terms: [GSM-7](https://smsmeteor.com/glossary/gsm-7), [UCS-2 (Unicode SMS)](https://smsmeteor.com/glossary/ucs-2), [Concatenated SMS](https://smsmeteor.com/glossary/concatenated-sms), [Character counter](https://smsmeteor.com/glossary/character-counter)

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Source: https://smsmeteor.com/glossary/segment (HTML). Generated by SMSMeteor from the same data as the page. Summary of the whole site: https://smsmeteor.com/llms.txt