Ethereum Unit Converter — Wei, Gwei, ETH, Finney, Szabo
Convert between wei, gwei, ether and other Ethereum denominations with full BigInt precision. Perfect for gas price math, smart-contract arithmetic, and EVM debugging. 100% local, no live rates.
Last updated:
CommentsEveryday units
The three you'll actually use: wei (contract math), gwei (gas), ether (UI).
| wei1 wei — the smallest unit, atomic integer. | 1000000000000000000 | |
| gwei10⁹ wei — the standard gas-price denomination. | 1000000000 | |
| ether10¹⁸ wei — the human-facing denomination. | 1 |
Rare / deprecated units
Kept for completeness — Solidity dropped these names in 0.7.
| kwei10³ wei — a.k.a. babbage, femtoether. Rare. | 1000000000000000 | |
| mwei10⁶ wei — a.k.a. lovelace, picoether. Rare. | 1000000000000 | |
| szabo10¹² wei — a.k.a. microether. Deprecated in Solidity 0.7+. | 1000000 | |
| finney10¹⁵ wei — a.k.a. milliether. Deprecated in Solidity 0.7+. | 1000 |
BigInt throughout: Numberloses precision past ~9 × 10¹⁵ wei (roughly 0.009 ETH), which is why every serious web3 library (ethers.js, web3.py) refuses to hand you a plain float for a balance.Frequently Asked Questions
How many wei are in one ether?
1 ether = 10¹⁸ wei = 1,000,000,000,000,000,000 wei. Wei is the smallest indivisible unit on the Ethereum blockchain; the EVM stores every balance and does every arithmetic operation in wei as an integer. 'ether' is just a label.
What is gwei used for?
1 gwei = 10⁹ wei = 0.000000001 ether. Gwei is the standard unit for expressing gas prices: '30 gwei per gas' is much more readable than either '0.00000003 ether' or '30000000000 wei'. Most wallets and RPC endpoints report gas prices in gwei.
Are szabo and finney still used?
Rarely. Solidity 0.7 (2020) removed the 'szabo' and 'finney' unit keywords from the language. They still appear in older documentation and legacy code, so this converter includes them for completeness. For new code use wei / gwei / ether.
Why is this precise when eth-converter.com uses Number?
JavaScript Number loses precision above 2^53 (≈ 9 × 10¹⁵). Since 1 ether = 10¹⁸ wei, any amount above 0.009 ETH exceeds that limit. Converters that use Number silently round large wei amounts; this one uses BigInt from input to output, so every digit is exact.
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