Most commonly, units of bitcoin are expressed in decimal exponents such as BTC (“bitcoins”), mBTC (“millibitcoins”) and μBTC (“bits”).

The satoshi is currently the smallest unit of the bitcoin currency recorded on the Bitcoin block chain. It is a one hundred millionth of a single bitcoin (0.00000001 BTC). The unit has been named in collective homage to the original creator of Bitcoin, Satoshi Nakamoto.

The next unit after a satoshi is a finney, named after the famous Bitcoin pioneer Hal Finney. 10 satoshis thus make 1 finney. 10 finneys make one bit.

Bits are not a distinct currency either but just another unit of Bitcoin, like cents are to dollars. 1 bitcoin is always equal to 1,000,000 bits. In other words, 1 bit is equal to 0.00000100 bitcoin or 100 satoshis. Another name for a Bit is a microbitcoin (sometimes abbreviated as µBTC). So 1 µBTC is the same as 1 Bit.

A millibitcoin (mBTC) is 0.001 bitcoins. Thus, 1 BTC = 1,000 mBTC or millibitcoin and 100,000 Satoshis = 1 mBTC.

100 satoshis = 10 finneys = 1 bit.