SMS Segment Calculator
Estimate GSM-7 or Unicode SMS segments, accounting for extension characters and whole surrogate pairs.
Start with your input
Edit the example or replace it with your own text.
How to use SMS Segment Calculator
- Load the example or paste your own input.
- Check the settings and run the tool.
- Review the result, then copy or download it.
What this tool helps you do
Check how a message’s characters affect its likely SMS segment count before pasting it into a sending platform. Basic GSM characters consume one unit and extension-table characters consume two. Text outside that alphabet switches to a Unicode count based on UTF-16 units. The report includes encoding, character and unit counts, segment count and remaining space in the last segment.
Format rules and limitations
The calculator uses typical capacities of 160 or 70 units for a single segment and 153 or 67 for concatenated segments. It avoids splitting a GSM escape pair or a supplementary Unicode character across a boundary. Sender types, carrier routes and concatenation headers can change real limits. It does not send messages, apply smart-character substitutions, validate delivery or calculate a bill. Your text is processed locally in the browser.
Example input
Hello! Your appointment is confirmed.
What should I check before relying on the output?
The calculator uses typical capacities of 160 or 70 units for a single segment and 153 or 67 for concatenated segments.
Is input uploaded?
Processing takes place in your browser. This tool does not send your input or selected files to a conversion API.