SMS length & segment calculator
Paste a message to see its encoding, its segment count, and its sending cost. This tool is free and needs no account. It runs in your browser.
One rate per segment. Carrier fees are passed through at cost. See pricing.
How SMS counting works
Carriers encode a text as GSM-7 or UCS-2. GSM-7 is a 7-bit alphabet that covers basic Latin letters and some symbols. UCS-2 uses 2 bytes per character and covers all other characters. One character outside the GSM-7 set changes the whole message to UCS-2. The limit then drops from 160 characters to 70. Long messages are split into concatenated segments of 153 (GSM-7) or 67 (UCS-2) characters, and you pay per segment. The extension characters € [ ] { } ~ ^ | \ stay GSM-7 but count as two characters.
FAQ
How many characters fit in one SMS?
160 characters if the message only uses the GSM-7 character set. If it contains any character outside that set (emoji, smart quotes, most non-Latin scripts), the whole message is encoded as UCS-2 and the limit drops to 70 characters.
What is an SMS segment?
Messages longer than one SMS are split into segments that carriers reassemble on the phone. Each segment reserves 7 bytes for reassembly headers, so concatenated segments hold 153 GSM-7 characters (or 67 in UCS-2) instead of 160 (or 70). You pay per segment, not per message.
Why did my message switch to UCS-2?
A single character outside the GSM-7 set, such as an emoji, a curly apostrophe (’), an em dash, or letters from most non-Latin alphabets, switches the entire message to UCS-2. The calculator lists the characters that caused the switch.
How much does it cost to send an SMS?
Price is per segment. A 3-segment message costs three times the per-segment rate. Hail charges one rate per segment and passes carrier fees through at cost. You can enter any provider's rate in the calculator.
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