How many text messages do ordinary heterosexual friends send a month?

If you are a bosom friend, you don't need to measure it by the number of short messages, but by the familiarity of the topics and relationships you talk about. If you send 400 messages a month and say something meaningless, you are not bosom friends, but you have a good chat, so you will gradually develop into bosom friends.

I have many friends, the most one is that I send 1400 messages a month, and the least one is only a few messages a month, but this does not affect our relationship, because we were familiar with each other before.

If you just met, you must be more frequent.