Wei
Wei alludes to the smallest denomination of ether (ETH), the currency utilized on the Ethereum network. For example, 1 ether (ETH) is equivalent to 1x1018 wei (which may likewise be addressed in exponential documentation: 1e18 wei).
As the price of Ether and other cryptocurrencies rises, the size of each blockchain transaction will in general decrease. For instance, in the event that ETH is priced at $10, one would require 10 ETH to make a $100 transfer. Be that as it may, assuming that ETH is priced at $150, just 0.67 ETH would be adequate to transfer a similar value in USD. Utilizing ether denomination might be irksome as the transaction size decreases.
In this unique circumstance, wei and different denominations of ether might be helpful for portraying small value transactions, particularly with respect to tiny measures of ETH that are normally utilized for transaction fees or while setting the gas limit of a transaction.
As introduced on the Ethereum technical reports, there are several different denominations of ether, each addressing a various of wei. Gwei and ether are among the most utilized denominations.
| Unit | Wei Value | Wei | Ether Value |
| Wei | 1 wei | 1 | 10-18 ETH |
| Kwei | 10³ wei | 1,000 | 10-15 ETH |
| Mwei | 106 wei | 1,000,000 | 10-12 ETH |
| Gwei | 109 wei | 1,000,000,000 | 10-9 ETH |
| Microether | 1012 wei | 1,000,000,000,000 | 10-6 ETH |
| Milliether | 1015 wei | 1,000,000,000,000,000 | 10-3 ETH |
| Ether | 1018 wei | 1,000,000,000,000,000,000 | 1 ETH |
Features
- A U.S. dollar is just detachable into 100 units — pennies — and the penny is the inseparable (atomic) unit of U.S. currency.
- The wei is named after Wei Dai, best known as the maker of the bitcoin ancestor "b-cash" and as the engineer of the Crypto++ library.
- A wei is to ether as a satoshi is to bitcoin — the two units are the smallest unit from which a client might make a transaction.
