A review of where we are with Bitcoin units

by Shaun Hoyes

The Bitcoin unit is probably one of the most overlooked subjects in the Bitcoin space. As with most things in Bitcoin, origin at best is unclear. In their July 1st blog post titled Breaking It Down: Bitcoin Units of Measurement, Blockchain.info established that 10 satoshis can be expressed as 1 finney. My assumption is that this unit was named after the late Hal Finney. This was an introduction that surprisingly did not get much attention, which is why I’m choosing to shed some light on it.

I first wrote about this back in September 2013 in a blog post titled Bitcoin Units. My then explanation of Bitcoin units, for the most part, continues to be consistent with standard use (accept for the addition of finney). Back then, everything was referenced in either satohis (シ) or whole BTC’s (Ƀ). Then Coinbase solidified bits as a more realistic unit of measurement given where the BTC/USD exchange rate continued to hover at.

The breakdown

Taking Blockchain.info’s recent analysis into consideration, I will provide an updated unit chart:

Unit name	BTC value
Bitcoin (BTC)	1 BTC
Centibitcoin, Cent-Bitcoin, bitcent (cBTC)	0.01 BTC
Millibitcoin, Milli-Bitcoin, millibit, mbit (mBTC)	0.001 BTC
Microbitcoin, microbit, bit (μBTC)	0.000001 BTC
finney	0.0000001 BTC
satoshi	0.00000001 BTC

Although from time to time I’ll hear people express Bitcoin value in milibits, today the most popular units used are BTC and bits. Amounts expressed in satoshis are common more among the bitcoin development community where numbers and the calculations behind them warrant more precision. In general, the least common references are centibitcoin (cBTC) and finney, however this is always subject to change.

Setting the rules

There is no governing body (yet) that dictates what Bitcoin units should be. As of now, there have only been a handful of players that have possessed the necessary influence in setting the Bitcoin units agenda. Other than that, most of the Bitcoin community has been content with referencing value in whole BTC, divisible by 8 decimal places. Although it would be nice to have a somewhat uniform approach to labeling each descending Bitcoin unit, this approach goes against Bitcoin’s grain and is probably too early to implement if it were possible at all. The closest we have to come to any form of Bitcoin uniformity as a currency is Bitcoin’s ISO 4217 currency code: XBTC. ISO 4217 is a currency code standard set by the International Organization of Standardization.

Nothing is written in stone

If Bitcoin ever approaches a serious level of world-wide adoption either as a currency or a store of value, I imagine there would be hundreds of thousands of unit names that compliment the world’s political and linguistic diversity. In the end, the innovation on top of the blockchain will translate into world recognition of this publicly audited ledger. For instance, Americans do not officially use the metric system, but regularly share flights with European nationals, who DO use the metric system. However we still manage to figure out how much fuel is needed for a cross-Atlantic flight. We share the same air and natural resources even though we have different time zones, and it seems to work.

The issue of naming Bitcoin units is one that will work itself out naturally. While now seen as a relatively minor issue, unit names will require providing education for those who plan to conduct activity on this network. Right now, a “finney” might not be a realistic unit to use for everyday activity simply because it represents value worth less than a penny ($0.01 USD). But there may be a place for it in the future as the Bitcoin network increasingly becomes a reliable transaction layer for exchanging value of the internet.