>>107589910It's a little tough to say. The Powerpuff Girls tended to be kind of inconsistent because the show was comedy first and a superhero show second. Sometimes they were fast enough to travel into the future, others they were harmed by a fuzzy hick dropping a giant rock on them. Although there was that one episode where they tried to join their universe's equivalent of the Justice League and they took part in tests of strength, speed, and field work, so I guess that's a good place to start. Looking at the PPG wiki page for that episode, Buttercup lifted a mountain (and the buff guy holding it up), Bubbles runs around the world in a little under seven seconds, and Blossom stops a bunch of meteors from hitting the earth.
So they're definitely a tier below guys like Superman, MMH, and the Flash, but they're seriously only a couple levels down from that. They'd be right at home in the Justice League if they were willing to let little kids join. Plus, given that they're five fucking years old, they could very well hang with the top tier heroes once they reach adulthood, assuming their physical abilities grow like a normal human being's would.