Ethereum Unit Converter

What is Ethereum Unit Converter?

Ethereum Unit Converter uses exact BigInt arithmetic — never floating point — so every conversion between Wei, Gwei, Ether and the larger units is precise to the last wei with no rounding errors or silent truncation. The smallest unit is Wei (the indivisible EVM base unit); the most common are Gwei (gas prices) and Ether (the main currency unit). Output is copy-ready, and the same terminology applies across all EVM chains.

The built-in Gas Fee Calculator turns total transaction cost (gasLimit × gas price) into Gwei, ETH and optional fiat in one step — the daily task for Ethereum developers and traders. Everything runs locally in your browser.

Ethereum Units Explained

What is Wei in Ethereum?

Wei is the smallest denomination of Ether, named after Wei Dai, a cryptographer. 1 Ether = 1,000,000,000,000,000,000 Wei (10¹⁸ Wei).

What is Gwei and why is it important?

Gwei (Gigawei or Shannon) is commonly used to denote gas prices on Ethereum. 1 Gwei = 1,000,000,000 Wei (10⁹). Gas prices are typically displayed in Gwei because it provides a convenient middle ground between Wei and Ether.

How do I calculate gas fees?

Gas fees are calculated by multiplying gas used by gas price (in Gwei). For example: 21,000 gas × 50 Gwei = 1,050,000 Gwei = 0.00105 ETH. This converter helps you convert between these units easily.

Why are Ethereum units named after people?

Many Ethereum units are named after pioneers in cryptography and computer science: Wei Dai (Wei), Charles Babbage (Kwei), Ada Lovelace (Mwei), Claude Shannon (Gwei), Nick Szabo (Szabo), and Hal Finney (Finney).

Why do gas calculations need BigNumber arithmetic instead of normal floats?

1 ETH = 10^18 Wei, far exceeding JavaScript Number precision (Number.MAX_SAFE_INTEGER = 2^53 - 1 = ~9*10^15). Computing 50 Gwei * 21000 gas as floats loses precision. This converter uses BigInt or BigNumber.js so 0.000000000000000001 ETH conversions stay exact.

What is the difference between gasUsed, gasPrice and gasLimit?

gasLimit is the MAX gas you authorize. gasPrice is what you pay per gas unit (in Gwei, post-EIP-1559 split into baseFee + priorityFee). gasUsed is what the EVM actually consumed. Your fee = gasUsed * effectiveGasPrice. Unused gasLimit is refunded automatically.

Are these unit names used on all EVM chains or only Ethereum?

Wei, Gwei and Ether terminology is shared across all EVM chains (Polygon, BSC, Arbitrum, Optimism, Base, Avalanche C-Chain). Native units differ in name (MATIC, BNB, AVAX) but the 1:10^18 base-unit ratio and Gwei gas-price convention apply identically.

Is this converter private — does my data leave the browser?

Yes, it is 100% private. All conversion and gas-fee math runs entirely client-side in your browser using JavaScript BigInt. No values, amounts or inputs are ever sent to any server, and no wallet, private keys or seed phrases are involved — this tool never asks for and never touches your keys.

How do I convert EIP-1559 maxFeePerGas to a total ETH cost?

Under EIP-1559 your effective gas price is baseFee + priorityFee, capped by maxFeePerGas (both in Gwei). Total fee = gasLimit × effectiveGasPrice. Example: a 21,000-gas transfer with maxFeePerGas = 30 Gwei and maxPriorityFeePerGas = 2 Gwei, where baseFee = 20 Gwei, pays 22 Gwei effective → 21,000 × 22 = 462,000 Gwei = 0.000462 ETH. Enter gasLimit and your effective (or max) Gwei price in the Gas Fee Calculator above to get the exact ETH and fiat cost.

Why does 1 Wei show as 0.000...001 ETH instead of 0?

Because 1 Wei is exactly 10^-18 ETH (and 10^-30 of a Tether unit). This converter derives its decimal precision from the largest unit, so even a single wei is represented exactly in every unit rather than being silently truncated to 0. Conversely, sub-wei amounts are impossible — Wei is the indivisible base unit — so a fractional-wei input like 3.14159 Wei is floored to a whole 3 Wei, and negative or malformed values are rejected with a visible invalid-input state.

Common Conversion Examples

• 1 Ether = 1,000,000,000 Gwei
• 50 Gwei = 0.00000005 Ether (typical gas price)
• 21,000 gas × 100 Gwei = 0.0021 ETH (standard transfer fee)
• 1 Gwei = 1,000,000,000 Wei