Ethereum (ETH) Gas Fees Explained: A Complete Guide

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What is Gas in Ethereum?

Gas is the execution fee paid for operations on the Ethereum blockchain. Inspired by cryptographic fuel, it powers smart contract operations. Each computational step in a transaction consumes gas, priced in gwei (1 gwei = 0.000000001 ETH).

Why Gas Exists?


How Gas Works

  1. Gas Limit: Maximum gas a user agrees to spend (set per transaction).
  2. Gas Price: Price per gas unit (in gwei), determined by market demand.
  3. Total Cost: Gas Used × Gas Price. Unused gas is refunded.

Example Calculation


Gas Price Table

OperationGas CostNotes
Basic Transaction21,000Standard transfer
Contract Creation53,000Higher due to complexity
SLOAD20Read storage
SSTORE100Write storage

👉 Track live gas prices


FAQs

1. Why do gas fees fluctuate?

Gas prices rise during network congestion as users compete for block space.

2. How can I reduce gas costs?

3. What happens if my gas limit is too low?

The transaction fails, and you lose the gas spent (no refund).


Key Takeaways

Note: Always verify gas prices before submitting transactions.