system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do text messages have character limits, and why is it measured as 145/1 until I use it up and it becomes 145/2?

Also, why is it that sometimes it stops me at 145/1 and doesn't go to 145/2?
gpt
The number after the / isn't related to characters, it's the number of SMS messages which will be used to send the text written. If your phone stops you at the 145 limit, it is doing the behaviour of older phones which only allowed a single text to be sent at a time.