What is SMS Character Limit, Encoding & Free Cost Calculator
Quick answer for you
If your message uses only plain English letters and common punctuation, one SMS = 160 characters. If it has any regional script (like Hindi) or an emoji, it becomes Unicode and one SMS = 70 characters.
When SMS length is longer than 160, it gets split into multiple parts (called concatenated SMS) and each part can hold fewer characters (153 for GSM‑7, 67 for Unicode).
How encoding changes what you pay
You typed a message and it cost more than you thought. That’s usually because of encoding.
GSM‑7 vs Unicode
You write a normal English message with periods, commas, numbers. It usually stays in GSM‑7.
Tip: GSM‑7 gives 160 characters in one SMS. If you go past that, extra parts are 153 characters each. Use plain characters to save credits.
Situation: You write in Hindi, Tamil, or add an emoji. That forces Unicode.
Tip: Unicode gives 70 characters in one SMS. Extra parts are 67 characters each. Unicode messages usually cost more.
GSM-7 (normal text):
- 160 = 1 SMS
- 161–306 = 2 SMS (153 each)
- 307–459 = 3 SMS
- 460–612 = 4 SMS
Unicode (emoji / special characters):
- 70 = 1 SMS
- 71–134 = 2 SMS (67 each)
- 135–201 = 3 SMS
- 202–268 = 4 SMS
How concatenation works (and why segments are smaller)
When an SMS is too long, the gateway breaks it into parts. Each part includes a small header to help phones reassemble the message, which reduces the usable character count per part.
Quick reference table
| Encoding | Single SMS limit | Per concatenated part |
|---|---|---|
| GSM‑7 | 160 | 153 |
| Unicode | 70 | 67 |
Tip:This is why a long message can cost two, three or more credits.
Easy examples to try
Example 1 – Plain English (GSM‑7)
- Text: “Your OTP is 123456. Do not share it.”
- Length: 33 chars → 1 SMS (GSM‑7)
Example 2 – Em dash may break GSM‑7
- Text: “You’re all set – welcome!”
- The em dash might not be in GSM‑7 → message becomes Unicode → counts as Unicode SMS
Example 3 – Hindi (Unicode)
- Text: “आपका OTP 123456 है।” → Unicode → counts against 70/67 limits
Example 4 – With emoji
- Text: “Delivery scheduled 🚚” → Emoji makes it Unicode → even short text costs more
Different SMS providers sometimes fix or change characters. Always do a small test batch with the exact message before you do large campaign.
How to calculate SMS credits and cost
Follow this simple method:
Step 1: Write your message
Step 2: Count characters
Step 3: Check encoding
- Only plain English → GSM-7
- Emoji / regional language → Unicode
Step 4: How message is split?
SMS can only send a fixed number of characters in one message. If your text is longer, it gets split into multiple parts.
- GSM-7 → 160 (1 SMS), then 153 per part
- Unicode → 70 (1 SMS), then 67 per part
At scale, small per‑SMS differences add up fast. Run this math before sending big campaigns.
Simple tips to save money and get better delivery
- Use plain characters (straight quotes, simple hyphens) if possible – They stay in GSM‑7.
- Don’t use emojis in high‑volume messages.
- Shorten long links with a link shortener.
- Keep OTPs and confirmations to one segment.
- If you send in regional languages, make separate lists for each language – don’t mix.
- Cut unnecessary words in your SMS. Shorter messages cost less and often read better.
Small edits – like replacing a curly quote with a straight one can save money when you send large batches.
Ready-to-use SMS templates
Transactional SMS (keep ≤1 segment)
- OTP: “Your OTP is 123456. Valid for 10 mins.”
- Payment: “Payment of ₹2,500 received. Txn ID: ABC123.”
- Shipping: “Order #1234 shipped. Track: LINK”
Marketing (aim ≤2 segments)
- Promo: “Flat 20% off on your next order. Use CODE20. T&C apply. Shop: LINK”
- Abandoned cart: “You left items in cart. Get 10% off to complete purchase: LINK”
Tip: Use short, clear CTAs – they get clicks and keep costs down.
FAQ (People Also Ask)
Q: How many characters in one SMS?
A: 160 for GSM‑7; 70 for Unicode.
Q: What makes an SMS switch to Unicode?
A: Any character not in GSM‑7, like regional scripts, many punctuation marks, and emojis.
Q: Why do concatenated SMS use fewer chars per part?
A: Each part includes a small header to help phones reassemble the message, which reduces the usable character count per part.
Q: Can I mix languages in one SMS?
A: Yes, but if you include a non‑GSM script, the whole message becomes Unicode and costs more.
Q: How do I check my SMS character count?
A: Use your gateway’s composer, a simple text editor, or the calculator below before sending.
