SMS Segment Calculator
Count SMS characters and billable message segments instantly. Check GSM-7 or Unicode encoding, spot characters that change your limit, and estimate sending cost.
Message input
Write or paste your SMS
The results update as you type. Line breaks and spaces count toward the message length.
Message analysis
Your SMS result
Every character is supported by GSM-7.
Encoding details
Characters affecting your message
Unicode characters
These characters are outside GSM-7 and change the complete message to UCS-2.
GSM-7 extension characters
These are valid GSM-7 characters, but each consumes two character units.
What Is an SMS Segment Calculator?
An SMS segment calculator checks a message's encoding, character usage, and number of transmitted SMS parts. Providers commonly charge for each segment, so a message that appears as one text on a phone can create several billable segments.
The calculator runs inside your browser. The message entered in the tool is not submitted to SaaSWonder.
SMS Character and Segment Limits
| Encoding | One segment | Concatenated segment |
|---|---|---|
| GSM-7 | 160 units | 153 units |
| UCS-2 / Unicode | 70 code units | 67 code units |
A long message uses a user data header so the receiving device can join its parts in the correct order. That header reduces the text capacity available inside every concatenated segment.
GSM-7 vs. UCS-2 Encoding
GSM-7 supports a limited alphabet used for many English-language messages. Certain supported symbols, including braces, brackets, the euro sign, and the caret, come from the GSM-7 extension table and consume two units.
If the message includes a character outside GSM-7, the entire message normally switches to UCS-2. Emojis, smart quotation marks, and many non-Latin scripts can trigger this change.
How the Cost Estimate Works
The tool multiplies segments per recipient by the recipient count and the price entered per segment. It provides a simple planning estimate.
Your final cost can differ because provider pricing, carrier fees, destination countries, sender types, and special routing rules vary. Confirm the final rate with your SMS provider.
Frequently Asked Questions
How many characters fit in one SMS?
A GSM-7 message supports 160 character units in one segment. A UCS-2 message supports 70 UTF-16 code units.
Why does a longer SMS use 153 or 67 units per segment?
Concatenated messages reserve some space for a header that identifies and orders the individual segments.
Do emojis increase SMS segments?
Usually. An emoji changes the message to UCS-2 and commonly consumes two UTF-16 code units.
Why can the character count differ from the unit count?
GSM-7 extension symbols consume two units, and some Unicode symbols such as emojis consume two UTF-16 code units.
Are SMS messages billed per segment?
Providers commonly charge each transmitted segment. Rates can vary by provider, destination, sender type, and carrier.