Three Ethereum denominations in one converter, with the math done in BigInt so the precision survives.
Ethereum’s native unit (ETH) is divisible into 10¹⁸ Wei — essentially Planck-scale precision for an internet currency. Gwei sits in the middle at 10⁹ Wei, and is the unit gas prices are quoted in. The converter below uses JavaScript BigInt throughout, so even values like 123,456,789,012,345,678 Wei round-trip without losing a single digit. Useful when reading a raw transaction object, debugging a smart-contract revert, or deciding whether a 30-Gwei gas price is reasonable today.
Computed with BigInt — exact integer math, no IEEE 754 rounding. Useful when reading transactions or sanity-checking gas estimates.
Wei (raw), Gwei (gas-price unit), or ETH (the human-readable amount).
Any positive decimal. Wei is integer-only because there's no smaller unit — fractional Wei inputs are truncated.
The arrow swaps the direction in one click. Conversions are exact for any value JavaScript BigInt can hold (effectively unlimited).
| Unit | In ETH | Use |
|---|---|---|
| 1 Wei | 10⁻¹⁸ ETH | Atomic unit; storage |
| 1 Kwei (Babbage) | 10⁻¹⁵ ETH | Rarely used |
| 1 Gwei (Shannon) | 10⁻⁹ ETH | Gas prices |
| 1 Szabo | 10⁻⁶ ETH | Rarely used |
| 1 Finney | 10⁻³ ETH | Rarely used |
| 1 Ether | 1 ETH | User-facing balance |
Number gives you ~15-17 significant digits. That's enough for ETH values up to about 9 ETH (because 10¹⁸ Wei needs 19 digits). For anything larger — or for sub-Gwei precision — BigInt is mandatory. Most production libraries (ethers.js, viem) standardise on BigInt for exactly this reason.
Block explorers like Etherscan show transaction values in ETH because that's the human-readable form. Under the hood, the value field is a hex string representing the Wei count. Pasting that hex into a parser, converting to decimal, and pasting here gets you back to ETH cleanly.