How is Message Cost Calculated?
Every compose screen shows what a message will cost before you send it. This page explains where that number comes from.
The Formula
Cost = recipients × segments × rate
- Recipients: the numbers that receive the message.
- Segments: how many SMS parts the message is split into.
- Rate: the price for each segment on the recipient's network and route. Your balance is in units or in currency, depending on your billing mode.
Segments
Long messages are split into segments, and each segment is charged separately.
| Encoding | Single message | Each segment of a longer message |
|---|---|---|
| GSM (standard letters, numbers and symbols) | 160 characters | 153 characters |
| Unicode (emoji and other special characters) | 70 characters | 67 characters |
| Message length | GSM segments | Unicode segments |
|---|---|---|
| Up to 70 characters | 1 | 1 |
| 71 to 160 characters | 1 | 2 or 3 |
| 161 to 306 characters | 2 | 3 to 5 |
| 307 to 459 characters | 3 | 5 to 7 |
- One special character is enough to switch to Unicode. Emoji, curly quotes pasted from word processors and many accented letters all do it. On To Individuals, the counter shows Unicode Encoding and names the character responsible.
- Some GSM symbols count twice:
^ { } [ ] ~ \ | €each use two characters. - Typed messages can be up to 1,071 characters, which is seven GSM segments.
Estimated and Exact Cost
The cost card on each compose screen shows:
- ESTIMATED COST: a price range based on your country's rates, with the number of recipients, pages and the Avg Rate.
- EXACT COST: click Calculate Exact Cost to price your actual recipients by network. A Network Breakdown shows the share of each network. For groups and files, DartPro prices a sample of your numbers and shows the Sample size.
When You're Charged
- When you send: DartPro deducts recipients × segments × the highest rate among your recipients' networks.
- As each message goes out: it's charged at its actual route's rate.
- When the broadcast finishes: any unused amount is refunded to your balance automatically.
Numbers DartPro can't route aren't charged.
Scheduled messages:
- To Groups and To File Contacts are charged when you schedule.
- To Individuals and From Template follow your Scheduled Message Billing setting, found under Settings > SMS Messaging:
- In Advance (Recommended) charges when you schedule.
- At Send Time charges when the message sends.
Not Enough Balance
If the cost is more than your balance, the compose screen shows Insufficient Credit (or Insufficient Balance for currency billing). It tells you how much you need and how much you're short by, and the send button stays disabled. Click Top Up Balance, or see Recharging Your Account.
Keeping Costs Down
- Stay in GSM. Replace emoji and curly quotes with plain characters.
- Watch the segment count. Trimming a few characters can save a whole segment on every message.
- Clean your list. Remove invalid and repeated numbers before you send.
- Check large sends first. Click Calculate Exact Cost before a big broadcast.