The total number of bitcoins that have already been mined; in other words, the current supply of bitcoins on the network.
The data is pulled from Blockchain in daily basis. You can also read everything you have to know for Bitcoins in the app.
Bitcoin is the original and most popular decentralized digital currency. It’s used by all types of people on every continent.
Bitcoins are created each time a user discovers a new block. The rate of block creation is adjusted every 2016 blocks to aim for a constant two week adjustment period (equivalent to 6 per hour.) The number of bitcoins generated per block is set to decrease geometrically, with a 50% reduction every 210,000 blocks, or approximately four years. The result is that the number of bitcoins in existence will not exceed slightly less than 21 million.
Speculated justifications for the unintuitive value "21 million" are that it matches a 4-year reward halving schedule; or the ultimate total number of Satoshis that will be mined is close to the maximum capacity of a 64-bit floating point number. Satoshi has never really justified or explained many of these constants.
This decreasing-supply algorithm was chosen because it approximates the rate at which commodities like gold are mined. Users who use their computers to perform calculations to try and discover a block are thus called Miners.
Bitcoin has no centralized issuing authority. The network is programmed to increase the money supply as a geometric series until the total number of Bitcoins reaches 21 million BTC. As of October 2012 slightly over 10 million of the total 21 million BTC had been created; the current total number created is available online in our application. To ensure sufficient granularity of the money supply, clients can divide each BTC unit down to eight decimal places (a total of 2.1 × 1015 or 2.1 quadrillion units).
Those who chose to put computational and electrical resources toward mining early on had a greater chance at receiving awards for block generations. This served to make available enough processing power to process blocks. Indeed, without miners there are no transactions and the Bitcoin economy comes to a halt.
Now you can see the total number of minded Bitcoins online or offline from this application for free.