it depends on a size of a frog, but they can easily jump 2-3 times their size, babies even higher then that, so a lid is a must, including when they soak. actually they tend to jump higher from their bath tubs lol.
in 12" high enclosures they can reach the top without jumping, depending on their side of course, my ornate female has no problems doing so, especially after her soak to prove the point how much she hates me doing anything to her home, all she needs to do is to stretch her legs a bit, it is our routine, she messes up everything after i clean it, then i go clean glass again and she tries to bite me.