One of the most common questions we get when sending SMS from our SRS System is what is the size of an SMS message?

The Answer depends. Each message is broken up into chunks of Characters and the billing is based on these chunks.

For a basic message, the first SMS is 160 Characters. If the message is more than 160 Characters then it’s broken up into two messages the first message is 153 Characters (the other 7 Characters tell the phone “You have more of this message coming”) This process is repeated as the message increases in size. In summary:

  • Up to 160 Characters is 1 Standard SMS Message
  • Up to 306 Characters is 2 Standard SMS Messages
  • Up to 459 Characters is 3 Standard SMS Messages
  • Up to 612 Characters is 4 Standard SMS Messages
  • Up to 765 Characters is 5 Standard SMS Messages
  • etc
  • Up to 1,377 Charecters is 9 Standard SMS Messages

This changes when you send Unicode SMS messages (ie messages with more than the limited Latin alphabet that English commonly uses) each character needs twice as much space for every Character so the first SMS is 70 Characters.

The chunks are billed as follows:

  • Up to 70 Characters is 1 Unicode SMS messages
  • Up to 134 Characters is 2 Unicode SMS messages
  • Up to 201 Characters is 3 Unicode SMS messages
  • Up to 268 Characters is 4 Unicode SMS messages
  • Up to 335 Characters is 5 Unicode SMS messages
  • etc
  • Up to 603 Characters is 9 Unicode SMS messages

Hope that helps work out the how much each message costs