In N52, approximately Kryptonian level strength and speed. Probably somewhat less durable (but still able to go toe to toe with Kryptonians / tank a nuke point blank). Has a "god" mode with bracelets removed that seems to buff her quite a bit but hard to tell how much, depends on the writer it seems. In her own comic she is mostly up against other gods / creatures etc and the emphasis is much less on feats than the likes of Superman. In Justice League it seems like she is generally the second most powerful hero to Superman but is a better warrior with less weaknesses and some neat magical gear.
Wonder woman fight kryptonian it's more like karate kid beat Silver age superman