I'm not too certain what the percentage of the reward is, but I know it gets split amongst the curators.

I would estimate it to be about 25% of the payout. Because I had one post that was $50 and the curators got $15 amongst them so that was about 25%. I'm not sure the exact number though. guess it also has a lot to do with how many people upvoted it and were involved in its curation