What sending SMS messages costs per month at scale.
Long texts split into billed segments and international rates vary enormously — both quietly inflate the bill. Trim copy and mind your country mix. Compare cheaper channels on the push notification calculator.
The SMS API Cost Calculator estimates your total monthly SMS spend by multiplying three inputs: the number of messages you send per month, the price per message charged by your SMS API provider, and the average number of segments per message. Segments matter because carriers bill in fixed chunks—typically 160 characters for plain text (GSM-7) or 70 characters for messages containing emoji or special characters (UCS-2). A message longer than one segment is split and billed as multiple messages, so a single 300-character text can cost two or three times the base per-message rate. The calculator combines these factors to show what your SMS program actually costs each month, rather than the deceptively low single-message price quoted on a pricing page.
The most useful thing this tool reveals is how segment count quietly multiplies your bill. Trimming a message from 165 characters to under 160, or dropping an emoji that forces UCS-2 encoding, can cut a message from two segments to one and reduce that portion of your spend by half. Before committing to a provider or a campaign volume, run your realistic average segment count—not the best case—since long links, unsubscribe footers, and merge fields all push messages past segment boundaries. Watch the trade-off between message length and cost: writing shorter, tightly encoded messages keeps you at one segment, while richer content that improves engagement may be worth the extra segments only if it lifts response rates enough to justify the added spend.
Per message, and a long message counts as several segments (about 160 characters each), each billed. Rates also vary widely by destination country and by whether the number is long-code, toll-free or short-code.
Keep messages under one segment (160 chars), send only where needed, and prefer cheaper channels (push, email, WhatsApp) when possible. In many countries carrier fees add to the base rate, so destination mix matters.
Cost at different volumes:
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