Circulating supply refers to the the amount of coins that are currently circulating in the market. The current circulating supply for bitcoin stands at 18.9 million.
Total supply is the entire future supply of coins, which in Bitcoin's case is 21 million, a level that will only be reached in 2140.
Spendable Supply refers to the number of bitcoins in the circulating supply that have not been lost (private key lost) or destroyed (sending BTC to invalid addresses) or technical peculiarities (first 50 BTC in the Genesis block are unspendable).
Spendable supply will always be lower than the theoretical supply and although this number is hard to gauge, it's estimated that around 3.79 million BTC have been lost.
Market cap is a simple calculation taking the current price of BTC and multiplying it by its circulating supply.
Circulating supply of coins x Price per coin = Total coin market capitalization
To calculate the Bitcoin market cap we can take the 18.9 million in circulation and multiply it by the current trading price for 1 BTC.
Fully diluted market cap measures the market cap with the total coins to ever be created in the calculation.
The table below calculates these metrics in real time:
| Bitcoin | Metric |
| Current Price | |
| Total Supply | 21,000,000 |
| Current Supply | |
| Market Cap | |
| Fully Diluted Market Cap |
| Halving | Date | Block | Block reward | Mined in period | % mined |
| Genesis | January 3, 2009 | 0 | 50 | 10,500,00 | 50% |
| Halving 1 | November 28, 2012 | 210,000 | 25 | 5,250,000 | 75% |
| Halving 2 | July 9, 2016 | 420,000 | 12.5 | 2,625,000 | 87.5% |
| Halving 3 | May 11, 2020 | 630,000 | 6.25 | 1,312,500 | 93.75% |
| Halving 4 | Expected March 2024 | 840,000 | 3.125 | 656,250 | 96.875% |
| Halving 5 | Expected 2028 | 1,050,000 | 1.5625 | 328,125 | 98.4375% |
| Halving 6 | Expected 2032 | 1,260,000 | 0.78125 | 164,062.5 | 99.21875% |