If you’ve been writing smart contracts for more than a week, you’ve already made the mistake of passing the wrong unit somewhere. You meant to send 1 ETH and accidentally sent 1 Wei. Or you hardcoded a Gwei value and your transaction fee calculation was off by a factor of a billion.
It happens to everyone. Ethereum’s unit system is powerful but unforgiving.
Why Ethereum Units Are Confusing
Ethereum doesn’t use decimals under the hood. Everything is an integer. When you write msg.value in Solidity or pass a value through ethers.js, you’re always working in Wei — the smallest unit.
Here’s the full breakdown:
- 1 Ether = 1,000,000,000,000,000,000 Wei
- 1 Ether = 1,000,000,000 Gwei
- 1 Ether = 1,000 Finney
- 1 Ether = 1,000,000 Szabo
Gwei is what you’ll use most for gas prices. Wei is what Solidity actually works with. Finney and Szabo show up in older contracts and documentation.
The Tool
Instead of doing this math in your head or keeping a conversion table open in another tab, we built a free browser-based converter that handles all of it instantly.
👉 Ether Unit Converter — freeapptools.co
Type any value in any unit and everything else updates in real time. It also shows live gas prices for Ethereum, Binance Smart Chain, and Polygon, with EIP-1559 base fees and max fees included. All values are copy-ready with one click.
Practical Use Cases
When you’re writing a Solidity payable function and need to set a minimum value in Wei, when you’re debugging a transaction and need to quickly verify what a gas price in Gwei translates to in ETH, when you’re building a dApp and need to display human-readable ETH values from raw Wei responses from the chain — this is the tool you reach for.
No Sign Up. No Ads. Just the Converter.
Everything runs in your browser. Nothing is sent to a server. It’s completely free and always will be.
Built by N3st3d Labs — we make free tools for developers and crypto builders at freeapptools.co
If you find it useful, bookmark it. You’ll need it again.