Every SMS sent from Grow is billed per segment, not per message. A segment is 160 characters. Write more than that and the message is cut into several segments, and each one is charged separately. A five segment message to 1,400 contacts is 7,000 billable segments, which is how a single blast turns into a few hundred dollars.
Use the calculator below before any bulk send. Write the message in and it works out the segments for you.
Write it the way a member will actually read it. Where a merge tag would go, type a real first name instead, and pick a long one rather than a short one so the count holds for everybody on the list.
Confirmed against a studio's Twilio billing report, May 2026.
Segments per message
1
160 characters per segment on GSM-7
Cost per message
AUD $0.0812
1 x $0.0812
Total to send
AUD $113.68
To 1,400 contacts
Emoji and special character check
Clean. Every character in this message is in the standard SMS alphabet, so you get the full 160 characters per segment. Add a single emoji and the limit drops to 70.
Why emoji cost so much more
Standard text is sent using an alphabet called GSM-7, which fits 160 characters into a segment. The moment a message contains one character outside that alphabet, the whole message switches to a different encoding called UCS-2, and the segment shrinks from 160 characters to 70. Nothing about the price per segment changes. The message simply needs far more segments to carry the same words.
| Encoding | Single message | Per segment once it splits |
|---|---|---|
| GSM-7 (plain text) | 160 characters | 153 characters |
| UCS-2 (anything with an emoji) | 70 characters | 67 characters |
Take a 150 character message. As plain text it is one segment. Add a single emoji and it needs three segments, so it costs three times as much for one character. Two things stack up to cause that: the limit drops to 67 characters per segment, and most emoji count as two characters rather than one.
It is not only emoji
Curly quotes and long dashes are the ones that catch people out, because they look identical to the straight versions on screen. Copy from Word, Google Docs, Canva or ChatGPT and you will usually paste a curly apostrophe without noticing, and the whole message drops to 70 characters per segment.
Type your copy directly into Grow, or paste it through a plain text editor first. The calculator above will name any character that pushes the message onto UCS-2.
Paste the message the member will get
Merge tags are replaced before the message is sent, so a template holding {{contact.first_name}} is not what gets counted. Twilio counts the finished message. Swap a realistic name in before you paste, and use your longest likely name rather than your shortest.
Curly brackets are also worth knowing about: they are legal in GSM-7 but each one costs two character slots rather than one, so leaving raw merge tags in the box will overstate the count.
Where the rates come from
The Australian rate is the one STRONG studios are actually billed, taken from a full month of a studio's Twilio billing report. New Zealand, Singapore and the United States come from the GROW Variable Fees schedule that Hapana Account Management supplied in April 2025. That schedule was issued for another brand, and Hapana confirmed at the time that rates vary between regions, so treat those three as a guide and check them against a real invoice.
Canada, the United Kingdom and Ireland have never been supplied. For those, take the rate straight off your Hapana invoice and enter it in the cost per segment box.
Two other things that get billed
An inbound SMS costs the same as an outbound one, so a campaign that invites replies is charged in both directions. Inbound calls are charged at the same per minute rate as outbound. Both were confirmed by Hapana Account Management.