Local planning utility
SMS Segment Calculator
Check the exact draft’s encoding and segment use before estimating a send.
How the calculation works
GSM-7 basic characters use one encoding unit and extension characters use two. A single GSM-7 message holds 160 units; concatenated messages use 153 per segment. Unicode uses UTF-16 units, with 70 in one message and 67 per concatenated segment. Emoji can use two units.
| Encoding | Single message | Multipart segment |
|---|---|---|
| GSM-7 | 160 units | 153 units |
| Unicode / UTF-16 | 70 units | 67 units |
Assumptions and limits
Smart encoding, transliteration, national-language tables, and sender-specific 152/66 limits are not modeled. The calculator sends no messages.
Record this tool result
Keep the exact text, reported encoding, encoding units, and segments together. Recalculate after the final punctuation or emoji change; the earlier result does not describe a revised sentence.
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