Gas Fee Calculator

What You Actually Pay to Use Ethereum

Every action on Ethereum costs gas: sending ETH, swapping tokens, minting NFTs, depositing into DeFi protocols. Gas measures computational effort, and you pay for it in ETH denominated in gwei (one billionth of an ETH). A simple transfer costs 21,000 gas units. A Uniswap swap might cost 150,000-300,000 gas units. The total fee equals gas units multiplied by the price per gas unit. Enter your transaction type and current gas price above to estimate your fee before submitting a transaction.

EIP-1559: Base Fee, Priority Fee, and the Burn

Since August 2021, Ethereum's fee mechanism has two components. The base fee is set algorithmically based on how full the previous block was. If blocks are more than 50% full, the base fee increases (up to 12.5% per block). If blocks are less than 50% full, it decreases. This base fee is entirely burned, permanently removing ETH from circulation. The priority fee (tip) is an optional payment directly to the block validator to incentivize faster inclusion. Users set a maximum fee they are willing to pay, and any difference between their max and the actual cost is refunded.

Understanding Gwei

Gas prices are quoted in gwei. 1 gwei = 0.000000001 ETH. At a gas price of 20 gwei, a basic ETH transfer (21,000 gas) costs 420,000 gwei = 0.00042 ETH. At $3,000 per ETH, that is about $1.26. The same transfer at 100 gwei costs $6.30. During extreme congestion (NFT launches, airdrop claims), gas prices have exceeded 500 gwei, pushing simple transfer fees above $30. Gas price trackers like Etherscan's gas tracker show current fees in real time.

Layer 2 Fees: A Different Order of Magnitude

Ethereum Layer 2 networks dramatically reduce costs while settling to Ethereum for security. After the Dencun upgrade (March 2024), L2 fees dropped by 90-99%. Typical costs: Arbitrum token swap $0.02-0.10, Optimism transfer $0.01-0.05, Base simple transfer under $0.01, zkSync token swap $0.05-0.20. For users performing regular DeFi operations, moving to an L2 can reduce gas costs from hundreds of dollars monthly to a few dollars.

Strategies to Minimize Gas Costs on Mainnet

If you must transact on Ethereum's base layer, timing matters significantly. Gas prices follow predictable patterns: lowest during US nighttime hours (roughly 2-6 AM UTC on weekdays), highest during US and European business hours. Weekend gas prices average 20-40% lower than weekday peaks. Avoid transacting during major events when competition for block space drives fees to extremes. Batch multiple actions when possible, and set transactions to a lower gas price if speed is not critical.

Failed Transactions Still Cost Gas

A transaction that reverts (fails to execute) still consumes gas because validators expended computational resources attempting to process it. Common causes include insufficient token approvals, slippage tolerance set too low on DEX swaps, and interacting with contracts that have changed state since you initiated the transaction. On mainnet at high gas prices, a failed complex transaction can waste $20-50. Always verify token approvals before swapping, set reasonable slippage tolerance (1-3% for most tokens), and use transaction simulation tools offered by wallets like Rabby and MetaMask to preview whether a transaction will succeed before you pay for it.

Frequently asked questions