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SMS segment calculator

Paste a text message to count its characters and segments, see whether it's GSM-7 or Unicode, and find the characters that make it longer than it looks.
Encoding
UCS-2
Characters
117
Segments
2
Left in segment
16

118 UTF-16 units. UCS-2 fits 70 in one segment, or 67 per segment once a message is split.

On Text My Event this is 1 text per guest, however many segments it takes. Segments matter for how a long text arrives and for providers that bill per segment, not for your Text My Event plan.

Characters that force Unicode

  • ’curly apostrophe
  • —em dash
  • 🎉U+1F389

Where they are

Hi {First name}! We’re so excited for Saturday — doors open at 6. Parking’s behind the hall. RSVP here: {RSVP link} 🎉

Use this message

Counts are for the text as typed. Words in braces like {First name} fill in per guest, so the sent length varies a little.

Your event
Text message · via Text My Event
Hi Jordan! We’re so excited for Saturday — doors open at 6. Parking’s behind the hall. RSVP here: textmyevent.com/s/k7Q2xR 🎉
What Jordan sees. Most phones join a split text back into one message.

Runs in your browser. What you type stays on this page unless you choose to carry it into a new event.

What it checks

Whether every character fits the GSM-7 alphabet. If one doesn’t, the whole message is sent as UCS-2 (Unicode), and the calculator highlights the characters responsible.

How many segments the message needs: 160 GSM-7 characters or 70 Unicode units fit in one, and 153 or 67 per segment once it’s split. Extension characters like € count as two, emoji usually count as two, and neither is split across segments.

On Text My Event, segments don’t change your cost. Each message to each guest is one text, however long.

How to use it

  1. 1Paste or type your message. The counts update as you type.
  2. 2Check the encoding. If it says UCS-2, look at the highlighted characters.
  3. 3Use the swap button to replace curly quotes and long dashes, or edit the text yourself.
  4. 4Copy the message, or choose Use this message to start an event with it.

Worked examples

Plain text: GSM-7

Only GSM-7 characters

Hi Sam! Dinner is at 7 on Friday at Luca's. Reply here if you're running late.

GSM-7 · 78 characters · 78 septets · 1 segment

One curly apostrophe: Unicode

The same message typed on a phone that curls apostrophes

Hi Sam! Dinner is at 7 on Friday at Luca’s. Reply here if you’re running late.

UCS-2 · 78 characters · 78 units · 2 segments · forced by ’

An emoji

Emoji always need Unicode, and most take two units

Party starts at 8! Bring a friend 🎉

UCS-2 · 35 characters · 36 units · 1 segment · forced by 🎉

Euro sign and braces

GSM-7 extension characters count as two

Tickets are €15 at the door [cash or card].

GSM-7 · 43 characters · 46 septets · 1 segment

Exactly 160 characters

The longest single GSM-7 segment

Reminder: the reunion picnic is Saturday at Riverside Park, shelter 3, from noon to 5. Bring a side dish and lawn chairs. Reply here with questions. See you all

GSM-7 · 160 characters · 160 septets · 1 segment

Assumptions

Counts follow the GSM 03.38 alphabet and standard concatenated SMS (a 6-byte header per segment). Carriers and phones can differ at the edges. Some convert characters before sending, and some phones show a split message in pieces.

Personalization tokens like {First name} are counted as typed. After they fill in for each guest, the length changes a little.

Text My Event can also send messages as rich messages or with a picture, where SMS segments don’t apply. Either way, it’s one text per guest.

Questions, answered

What is an SMS segment?

A single SMS carries 140 bytes. That's 160 characters in GSM-7 or 70 in Unicode (UCS-2). A longer message is split into segments with a small header each, which leaves 153 or 67 characters per segment. Most phones join the segments back into one message.

Why did my message switch to Unicode?

One character outside the GSM-7 alphabet switches the whole message to UCS-2, which roughly halves how much fits in a segment. The usual culprits are curly quotes and apostrophes, long dashes, and emoji, which phones often insert for you. The calculator highlights them, and one button swaps smart punctuation for plain characters.

Do segments change what I pay on Text My Event?

No. Text My Event counts one text per guest per message, however many segments it takes. Segments matter for how a long text displays on older phones and for SMS providers that bill per segment.

Why do some characters count as two?

GSM-7 has an extension table for characters like €, [, ], {, }, \, ~, ^ and |. Each one is sent as an escape code plus the character, so it uses two of the 160 slots.

Does an emoji count as one character?

It looks like one, but most emoji are two UTF-16 units, so they use two of the 70 slots in a Unicode segment. Some emoji are built from several pieces and use more.

How are texts counted?

One message to one guest is one text, however long it is. A message to 50 guests uses 50 texts, with or without emoji or links. Texts that fail to deliver don't count.

Keep planning

Reviewed November 2, 2026.