You can calculate how many bitcoins are theoretically in existance by simply counting the number of blocks and refferencing issuance schedule. The blockchain wi

You can calculate how many bitcoins are theoretically in existance by simply counting the number of blocks and refferencing issuance schedule. The blockchain will not tell you what these bitcoins are worth in any other currency; nor will it tell you how many of these bitcoins are spendable by anyone (eg. did the owner loose the key).