Ethereum Gas Calculator

Gas is the unit that measures the computational work required to execute operations on the Ethereum network. Every operation — from a simple ETH transfer to a complex smart contract interaction — consumes a specific amount of gas. Gas prevents abuse of the network by ensuring each computation has a cost. You pay gas fees in ETH (in gwei units) to compensate validators who process your transaction.

Gwei is a denomination of ETH used for gas prices. 1 ETH = 1,000,000,000 gwei (1 billion gwei). Gas prices are quoted in gwei because the values are easier to work with — saying '20 gwei' is clearer than '0.00000002 ETH'. After EIP-1559, gas price consists of a base fee (burned) plus a priority fee (tip to validators).

The gas limit is the maximum amount of gas you're willing to let a transaction consume. For a simple ETH transfer, 21,000 gas is always sufficient. For smart contract interactions, you set a higher limit (e.g. 200,000) to ensure the transaction doesn't run out of gas. Unused gas is refunded — you only pay for gas actually consumed. If gas runs out mid-execution, the transaction fails but you still pay the gas used.

EIP-1559 (August 2021) replaced the first-price auction model with a base fee + priority fee model. The base fee is set algorithmically by the network based on demand and is burned (destroyed), reducing ETH supply. The priority fee (tip) goes to validators. You set a max fee (maximum total you'll pay) and the actual cost is base fee + priority fee. This made fee estimation more predictable.

Each EVM opcode has a fixed gas cost based on its computational complexity. Reading data from storage costs 100-2100 gas. Writing to storage costs 20,000 gas (first write) or 2,900 gas (update). A simple ETH transfer (no code) always costs exactly 21,000 gas. ERC-20 transfers cost ~65,000 gas because they execute contract code. Deploying a contract costs much more (500K–3M+ gas) depending on bytecode size.

Layer 2 networks like Arbitrum, Optimism, Base, and Polygon process transactions off-chain and periodically post batches to Ethereum mainnet. This dramatically reduces per-transaction costs — often 10-100x cheaper than mainnet. However, L2 transactions still use gwei and gas units, just at lower amounts. This calculator focuses on Ethereum mainnet; L2 costs vary by network.