There are hundreds of workouts that can indicate what you are ready to run. As coaches are always trying to invent the wheel. But I think the one that really worked for me and maybe lots of other people (in high school) was the classic 8x400. I think if you can do 8x400@65, 1 minute break you’re ready for a 4:20
In college, 10x400@60 with one minute break tell me you should be around the 4 minute mark.
There are other workouts you need to be doing ( obviously), so don’t just go out and run this every workout ;)