What is a good mile time for a middle school boy?

4:40.

Anything under 6 is good. Anything under 5:30 is great. Under 5 and you have serious potential or started shaving in 5th grade.

Don't worry about what is good or not, I think you should try one season and see if you like it. I had the same thoughts in middle school and decided not to join because I was afraid of being too slow. In middle school, it's all about trying sports to see if you like them.

I think you should sign up! To answer your question, if you can run under 6 minutes in middle school, that is pretty good.

Also, does middle school mean 5th grade, or does it mean 9th grade? Middle school covers a huge range in this country. A good time for one is a lot different than a good time for the other.

If you're thinking about doing track, just go ahead and do it. See what the training is like, and try racing different distances. And mostly just worry about what a good time is for you. You can start off in track/XC with terrible times and no physical fitness whatsoever and end up as a key player on a HS varsity team if you stick with it.