Use this site: http://steem.supply/rewards
The value is in STU and not SBD.

Example: you see near your post $100. In order to understand how much you will get, we will talk form now on in STU whenever we refer to the numbers the Steemit UI is showing. So you actually see near your post 100 STU.
Out of this, you give away 25% from your STU to curators.
You remain with 75 STU.
This amount is split 50 / 50, with the following algorithm:

the first half is given in SBD, in the exact amount shown by division. In our case, half of 75 is 37.5. So you get half of your rewards as 37.5 SBD
the second half is given in Steem Power, at the current feed price (the internal Steemit price for STEEM) in USD. So you get $37.5 worth of Steem Power. If the current feed price of STEEM is, let's say $6, you get $37.5 / $6 = 6.25 Steem Power.