There are two ways to look at it.
In order to understand the value of the daily reward pool of the steem there is a formula
new_steem = ( ( virtual_supply * current_inflation_rate ) / ( 10000 * BLOCKS_PER_YEAR ) ) * CONTENT_REWARD_PERCENT
However, one of the best ways to find out about the steem rewards pool is to access the information available on the website called steemd.com. This sit gives lot of statistical insights. At the time of writing this post, i found that the rewards fund as on date was 778,332 steem which is equivalent to $614,882.
This value keeps changing with the change in prices of steem. Total supply of steem has reached 299,512,603 Steem. Total Market capitalization is $236,615,611 according to the statistics available on steemd.com
The easiest way is to go to steemworld.org and log on to your page.
You will see on the left hand side loads of different heading tabs. Click on system info. This will open up all the information about the Steemit blockchain.
Currently as of right now there is 779,245.656 STEEM in the reward pool with a total of 241,423.829 STEEM in pending rewards. This changes all the time but is nice to know these things.
Steemworld.org is one of those tools that you should be using to understand your account and what is happening on steemit.
Your log in to the site would be https://steemworld.org/@alan369