SMS Length Calculator
Count characters, calculate SMS message parts, and check encoding type. Supports GSM-7 (160 chars) and Unicode (70 chars) encoding. Know exactly how many segments your SMS will use before sending. Essential for SMS marketing cost optimization.
✨ Optimize your SMS messages for cost and delivery
Understanding SMS Character Limits
SMS character limits depend on the encoding type used. Understanding these limits is crucial for SMS marketing to control costs and ensure messages display correctly on all devices.
SMS Encoding Reference
| Encoding | Single SMS | Multi-part SMS | Characters Supported |
|---|---|---|---|
| GSM-7 | 160 characters | 153 per part | Basic Latin, numbers, common symbols |
| Unicode (UCS-2) | 70 characters | 67 per part | All characters, emojis, non-Latin scripts |
Frequently Asked Questions
1. What is an SMS length calculator?
An SMS length calculator counts characters in your text message and tells you how many SMS parts (segments) it will be split into. Standard SMS supports 160 characters (GSM-7) or 70 characters (Unicode). Messages exceeding these limits are split into multiple parts, which affects cost. Our calculator detects encoding automatically.
2. What is the difference between GSM-7 and Unicode SMS?
GSM-7 encoding supports basic Latin characters, numbers, and some symbols (160 chars per SMS). Unicode (UCS-2) supports all characters including emojis, Chinese, Arabic, Hindi, etc. (70 chars per SMS). If your message contains even one Unicode character, the entire message uses Unicode encoding, reducing the character limit.
3. How are multi-part SMS messages handled?
When a message exceeds 160 (GSM-7) or 70 (Unicode) characters, it's split into multiple segments. Each segment uses some characters for concatenation headers: GSM-7 drops to 153 chars/segment, Unicode drops to 67 chars/segment. Carriers reassemble segments on the recipient's phone, but each segment is billed separately.
4. Is this tool free?
Yes, completely free with no signup. Calculate unlimited SMS lengths. All processing happens in your browser—your message text never leaves your device.
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