Ethereum: How can I know the gas and gas limit when sending a transaction?

About Ethereum Gas and Gas Limits

When interacting with the Ethereum network, it is essential to understand how gas is allocated and limited during transactions. In this article, we will dive into the basics of gas and gas limits and provide guidance on how to determine them when sending a transaction.

What are gas and gas limits?

In Ethereum, gas refers to the number of operations required to execute a transaction on the blockchain. Gas limit, on the other hand, is the maximum amount of gas that can be allocated to a transaction during a transaction.

When sending a transaction, the Ethereum network tries to find a balance between execution time and gas efficiency. The most expensive gas method will be executed first, until it reaches its limit or cannot be paid in full. This ensures that transactions are executed efficiently and without excessive fees.

Calculating Gas and Gas Limit

To calculate gas and gas limits for your transaction:

• Transaction Parameters: Identify your transaction parameters using contractAddress, from address, to address, value, and any additional data.

• Gas Estimation

  : Use an Ethereum gas calculator or a library like Web3.js to estimate the gas required for each transaction in your contract function.

For example:

const web3 = new Web3(url);
const txParams = {
from: account.address,
to: contractAddress,
value: 10n, // blank
};
// Estimate gas for each transaction
const gasEstimates = [];
for (const op in txParams) {
const gasEstimate = estimateGas(txParams[op], web3);
gasEstimates.push(gasEstimates);
}
// Determine total gas limit
const totalGasLimit = Math.max(...gasEstimates);

Determining Gas Limits

To determine gas and gas limits:

• Check your contract’s gas limit: Review your contract’s gas limit documentation or interact with the developer to understand what is expected.

• Gas Estimation: Use an Ethereum gas calculator or a library like Web3.js to estimate the gas required for each transaction in the contract function.

For example:

const web3 = new Web3(url);
// Estimate gas for a specific transaction operation
const txOp = txParams["gasUsed"];
const estimateGas = estimateGas(txOp, web3);
// Determine the total gas limit based on the estimated gas limit and the contracted gas limit
const totalGasLimit = Math.max(estimatedGas, 100000); // assuming 100k as the contracted gas limit

Best Practices

• Gas Estimation: Always estimate gas for each operation to avoid unexpected gas shortages or penalties.

• Check Contract Gas Limit: Review contracts and their gas limits before deploying them on your network.

• Keep Gas Allocation Flexible

  : Assign gas so that you can adjust it to your needs during transactions.

By understanding how to determine gas and gas limits, you will be better equipped to optimize your transactions for maximum performance and efficiency on the Ethereum network.