Impossible without test scores and a GPA helps.
Regardless, if you have a 3.8+ and 33 ACT or 1500 SAT, you probably have a 5% chance. 4.0 and 36/1600 won’t up much although GPA is more important than test scores at that point.
If you’re scores are below that, you have a less than 5% shot. To have more than that, you need to be URM, legacy, related to a big donor, or athlete.
Essays and letters of rec matter a lot. JHU will be higher than Harvard and Stanford but gets tougher every year.