BYTETOOLS

SMS Character Counter

Count SMS characters the way carriers bill them: GSM-7 or UCS-2 encoding, 160/153 and 70/67 segment maths, plus an estimate of what a send costs.

A single GSM-7 message holds 160 characters before it has to be split.

0
Characters
GSM-7
Encoding
0
Septets used
0
Segments
160
Per segment

Cost estimate

0
Billable segments
—
Estimated cost

Carriers bill per segment, per recipient. The currency is whatever you typed the rate in — this is arithmetic, not a price lookup.

An escape pair is never split across a segment boundary, so a long message full of { } or € can need one segment more than a plain division suggests. Everything is computed in your browser; no message is sent, stored or uploaded.

What is the SMS Character Counter?

An SMS is not billed by characters but by segments, and how many characters fit in a segment depends on the encoding.

  • Full GSM 03.38 basic and extension table detection, character by character
  • Automatic UCS-2 fallback with the exact characters that caused it listed
  • One-click replacement of curly quotes, dashes and other typographic culprits
  • Correct 160/153 and 70/67 segment maths, never splitting an escape pair
  • Cost estimate from your own carrier rate and number of recipients
  • Entirely client-side — no message is transmitted, logged or stored

How to use the SMS Character Counter

  1. 1

    Type or paste the SMS you are about to send.

  2. 2

    Read the encoding, the septet or unit count, and how many segments it will cost.

  3. 3

    If it switched to UCS-2, review the offending characters and swap in GSM-safe ones.

  4. 4

    Enter your carrier's price per segment and the recipient count for a cost estimate.

About the SMS Character Counter

An SMS is not billed by characters but by segments, and how many characters fit in a segment depends on the encoding. If every character belongs to the GSM 03.38 alphabet the message is packed seven bits per character and holds 160. One character outside that alphabet — a curly quote, an em dash, an emoji — switches the whole message to UCS-2 and capacity drops to 70.

This counter tests every character against the GSM basic table, flags the ones forcing UCS-2 alongside their Unicode code points, and offers to swap the common typographic culprits for GSM-safe equivalents in one click. Extension-table characters such as braces, brackets, tilde, backslash, caret and the euro sign are counted as two septets each, because that is how they are actually sent.

Segment maths follows the concatenation rules: 153 septets or 67 UCS-2 units per part once a message splits, with escape pairs and surrogate pairs never broken across a boundary. Enter your own carrier rate and recipient count for a cost estimate. Everything is computed 100% locally in your browser — no message is sent, stored or uploaded.

Frequently asked questions

How many characters are in one SMS?

160 if every character is in the GSM 03.38 alphabet, or 70 if any character falls outside it and the message has to be sent as UCS-2. Once a message spans more than one segment those drop to 153 and 67, because each part carries a header.

Why did my SMS become two messages?

A single character outside the GSM alphabet — most often a curly apostrophe pasted from a word processor, an em dash or an emoji — forces the whole message into UCS-2 and cuts capacity from 160 to 70. The offending characters are listed here so you can replace them.

What is the difference between GSM-7 and UCS-2?

GSM-7 packs each character into seven bits using a fixed 128-character alphabet, so 160 fit in a segment. UCS-2 uses 16 bits per unit and can carry any character, but only 70 fit. Carriers choose the encoding automatically from the message content.

Which characters count as two in an SMS?

The extension-table characters — caret, curly braces, square brackets, tilde, pipe, backslash and the euro sign — are sent as an escape plus a code, so each uses two septets. They still look like one character, which is why messages containing them split earlier than expected.

How is SMS cost calculated?

Carriers bill per segment, per recipient, so a two-segment message to 500 people is 1,000 billable segments. Enter your own rate above and the tool multiplies it out — this is arithmetic against a number you supply, not a price lookup.

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