Looks like there might be another 25 episodes of the My Hero Academia in the pipeline. A look under the hood of the official anime site http://heroaca.com/ has shown slots for 39 episodes, with image available labels through 38. If this is accurate, with the spring 2016 run of 13 episodes, then last weekend's preview/recap, the figure of a possible 25 or 26 episodes is arrived at.
There's also new manga cover art to look at
My Hero Academia Volume 13 Cover pic.twitter.com/kecQ9DsNgp— YonkouProductions (@YonkouProd) March 27, 2017