Wei / Ether Converter
Convert between Wei, Gwei, Finney, and Ether with full BigInt precision. No floating point errors.
ETH Unit Converter
Convert between Wei, Gwei, Finney, and Ether with full BigInt precision — no floating point errors.
Ethereum unit conversion table
| Unit | Wei equivalent | Common name | Typical use |
|---|---|---|---|
| wei | 1 | wei | Smallest unit — contract values, balances |
| kwei | 1,000 (10³) | babbage | Rarely used |
| mwei | 1,000,000 (10⁶) | lovelace | Rarely used |
| gwei | 1,000,000,000 (10⁹) | shannon | Gas prices, EIP-1559 fees |
| microether | 10¹² | szabo | Occasional tooling |
| milliether | 10¹⁵ | finney | Occasional tooling |
| ether | 10¹⁸ | ETH | Balances, transfers, staking |
1 Ether = 1018 Wei = 109 Gwei. 1 Gwei = 109 Wei.
What are Ether denominations?
Ether is divisible into smaller units, similar to how a euro divides into cents. The smallest unit is Wei: 1 Ether equals 10^18 Wei. Gwei (10^9 Wei) is the unit most commonly used for gas prices, while Finney (10^15 Wei) and Szabo (10^12 Wei) appear less often in modern tooling.
Because these conversions span 18 orders of magnitude, floating-point arithmetic can silently lose precision. This converter uses BigInt throughout, so every result is exact — no rounding errors even for very large values.
Features
- Convert between Wei, Gwei, Szabo, Finney, and Ether
- Exact BigInt arithmetic — no floating-point drift
- Accepts arbitrarily large values
- Instant, bidirectional conversion as you type
- 100% client-side — nothing is sent to a server
When to use it
Use it when reading gas prices reported in Gwei, checking a transaction value shown in Wei on a block explorer, writing amounts into Solidity contracts, or reconciling token balances that use different decimal places.
Frequently asked questions
How many wei are in 1 ETH?
Exactly 1,000,000,000,000,000,000 wei (10¹⁸). Ether has 18 decimal places — wei is its smallest indivisible unit, the same role a cent plays for a euro.
How many gwei are in 1 ETH?
1,000,000,000 gwei (10⁹). Gwei sits between wei and ether: 1 gwei = 10⁹ wei, and gas prices are almost always quoted in gwei.
Is gwei the same as wei?
No — they are different denominations of the same currency. Wei is the base unit; gwei is a billion wei. Confusing them is a 9-order-of-magnitude error, the most expensive typo in Ethereum.
Why is gas priced in gwei?
Gas fees are small fractions of an ether — typically 0.000000001 to 0.0000001 ETH. Quoting them in gwei keeps the numbers readable (5 gwei instead of 0.000000005 ETH).
Does this converter handle large numbers precisely?
Yes — it uses BigInt arithmetic throughout, so no floating-point rounding even for very large values. JavaScript's native numbers lose precision above 2⁵³; this tool does not.