It is impossible to calculate the post rewards because it is totally depend on the cryltomarket .
If we see dominance in a Bitcoin more than 45 percent if seems that there is 45 percent Bitcoin in the market.so then the price of steemit also varies with Bitcoin price.
Post reward are being calculated on basic steem power but steem power can be accumulated up and down so it is depended on Bitcoin so we cannot calculate the proper post rewards in a musing.
I can evenly says that post rewards in steemit cannot be calculated by the owner of the coin steemit because if big whales buy steem coin that no doubt of decrease the price of steem and the price increase as same as if whales sales the steem than the price will suddenly comes down.
So there is no way to calculate the reward lost we only get an idea that iwe have earned this much dollar only.