Each SMS segment sent counts as one reminder.

A message may use more than one reminder depending on:

You can estimate reminder usage using the reminder calculator in your account settings.

Each text message is sent in segments.

One segment = one reminder consumed.

Even if a message appears as a single text on a phone, it may have been sent using multiple segments.

For example:

The answer depends on the character format used in the message.

If your message only contains standard characters, the limit is:

160 characters per segment

If your message contains Unicode characters, the limit becomes:

70 characters per segment

Unicode characters include things like:

If even one Unicode character is present, the entire message must be sent using Unicode format.

Modern phones support SMS concatenation.

This means longer messages are:

In the past, these would appear as multiple messages arriving quickly one after another.

Reminder usage is based on the number of SMS segments required to send your message.

Even if your message appears as a single text message, it may require multiple segments, which means multiple reminders will be consumed.

This mirrors how SMS providers charge for message delivery.

Your account includes a reminder calculator that estimates how many reminders your message will consume.

You can find it in:

Account Settings

As you type your message, the calculator will show:

You can also see reminder usage in the Google Calendar add-on by opening an appointment after saving your reminder message.

Note: The add-on calculates the reminder usage after the message is saved, not in real time.

Your reminder message may include dynamic fields that insert information automatically.

These fields affect the total character count.

Because calendar titles and addresses vary in length, the exact reminder usage may vary for each appointment.

You can open the appointment in the app to see the exact number of reminders that will be consumed.

Including a URL or website link in your message can significantly increase the character count.

This may cause your message to require multiple SMS segments, which increases reminder usage.

If Appointment Confirmations are enabled, an additional message is automatically appended to your reminder.

Example appended text:

Confirm or cancel:
​https://www.smsreminder.co/confirmation/ZwhFHBRK2wq9sM6KGME_M

This appended message uses 81 characters, which is included in the character limit calculation.

The reminder calculator automatically accounts for this when estimating reminder usage.

If you'd like to reduce the number of reminders consumed, consider the following:

Most messages under 160 characters will use only one reminder.

Many businesses send:

Choose the schedule that works best for your business.

Emoji and certain accented characters can switch the message to Unicode format, reducing the character limit to 70 characters per segment.

Copying text from documents can introduce hidden formatting characters that increase the character count.

It's best to type the message directly into the editor.

Website links can consume many characters and increase the number of segments required.

Shorter values for {location} and {from} will reduce the overall message length.

Turning off appointment confirmations removes the 81-character confirmation message, reducing reminder usage.