How to Convert Ether to Wei, Gwei, Finney & Szabo (Free Tool)

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 br