How long can an SMS be?
One SMS holds 160 characters if every character belongs to the GSM 7-bit alphabet, and 70 characters otherwise. Longer messages are split into segments of 153 or 67 characters, and each segment is billed as one SMS by most providers.
An SMS carries 140 bytes. The GSM 7-bit alphabet (defined in the 3GPP TS 23.038 standard) packs each character into 7 bits, hence 160 characters. As soon as one character is outside that alphabet, the whole message switches to UCS-2, which uses 16 bits per character: 70 characters.
| Encoding | Single SMS | Per segment when split |
|---|---|---|
| GSM 7-bit | 160 | 153 |
| Unicode (UCS-2) | 70 | 67 |
Split messages lose a few characters per segment because each part carries a small header that lets the phone put the message back together.
Characters that cost more
- Extension characters
€ [ ] { } \ ~ ^ |are in the GSM alphabet but take two slots each. - Curly quotes ’ “ ”, the en dash –, the ellipsis … and non-breaking spaces are not in the GSM alphabet. Pasted from a word processor, a single curly apostrophe turns a 160-character message into three segments. The "Replace curly quotes, dashes and ellipses" button swaps them for their plain equivalents.
- Accented letters: é, è, à, ù, ì, ò, ä, ö, ü and ñ are in the GSM alphabet. á, í, ó, ú, ê, â and lowercase ç are not. The alphabet only has the capital Ç; some phones replace ç with it, others switch to Unicode.
- Emoji always force Unicode, and most take two UCS-2 units.
The SMS card above lists every character that is not in the GSM alphabet and highlights it in the text, so you can decide whether to replace it.
Good to know
This counter applies the default GSM alphabet. Some networks and phones also support national language tables (for example for Spanish, Portuguese or Turkish) that add a few accented letters; support varies, so the default alphabet is the safe assumption. Bulk SMS platforms may also apply their own replacements before sending. Use the segment count here as the figure to budget for.
For messaging apps (WhatsApp, iMessage, RCS), these limits do not apply. For social posts, see the X character counter.
Frequently asked questions
How many characters are in one SMS?
160 characters with the GSM 7-bit alphabet, or 70 if the message contains any character outside it, such as an emoji or a curly apostrophe.
Why is my SMS limited to 70 characters?
Your message contains at least one character outside the GSM alphabet, which forces Unicode encoding. The SMS card shows which character it is; replacing it often brings you back to 160.
Why are long SMS split into 153 characters?
Each part of a long SMS carries a header that lets the receiving phone join the parts. It takes the space of 7 GSM characters (or 3 Unicode characters), leaving 153 or 67.
Does the euro sign count as two characters in an SMS?
Yes. € belongs to the GSM extension table, like [ ] { } \ ~ ^ |, and each of those takes two of the 160 slots.
Do spaces and line breaks count in an SMS?
Yes. Each space and each line break uses one character of the message.