estimateGas - SDK

Returns an estimate of the amount of gas that would be required to submit a transaction to the network.

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Returns an estimate of the amount of gas that would be required to submit a transaction to the network.

An estimate may not be accurate since there could be another transaction on the network that was not accounted for, but after being mined affects the relevant state.


transactionobjectThe transaction to estimate gas for.

transaction object parameters

tostringDATA, 20 Bytes - The address to the transaction is directed to.
fromstringDATA, 20 Bytes - (optional) The address the transaction is sent from.
gasPrice?number / stringQUANTITY - (optional) Integer of the gasPrice used for each paid gas.
data?stringDATA - (optional) Hash of the method signature and encoded parameters. For details see Ethereum Contract ABI
value?numberQUANTITY - (optional) Integer of the value sent with this transaction
nonce?stringA nonce is a value that represents the number of transactions sent by the sender's address, ensuring the transactions are processed in order and preventing replay attacks.
gasLimit?stringthe maximum gas allowed.
chainId?numberoptional the Id of the transaction chain.
type?numberOptional This is the type of transaction.
accessList?array of stringsThe accessList is an optional transaction parameter that specifies addresses and storage keys a transaction interacts with, enabling gas cost optimization and compatibility with future Ethereum upgrades.
maxPriorityFee?numberThis describes the maximum priority fee for this transaction.
maxFeePerGas?numberThis is the maximum fee per gas for this transaction.
ccipReadEnabled?booleanThis specifies if the CCIP read is enabled.


Promise<BigNumber>objectReturns an estimate of the amount of gas that would be required to submit the transaction to the network. This is an estimate of the amount of gas required to submit the given transaction to the network. An example of the output is BigNumber { _hex: '0x651a', _isBigNumber: true }.

Example Request and Response

Prerequisite: You will need to install the Alchemy SDK before making requests with it.

The commands for installing it using npm or yarn are given below:

npm install alchemy-sdk
yarn add alchemy-sdk


Here is an example of how to make an estimateGas request using the Alchemy SDK:

// Imports the Alchemy SDK
const { Alchemy, Network, Utils } = require("alchemy-sdk");

// Configures the Alchemy SDK
const config = {
    apiKey: "demo", // Replace with your API key
    network: Network.ETH_MAINNET, // Replace with your network

// Creates an Alchemy object instance with the config to use for making requests
const alchemy = new Alchemy(config);

const main = async () => {
    const response = await alchemy.core.estimateGas({
        // Wrapped ETH address
        to: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
        // `function deposit() payable`
        data: "0xd0e30db0",
        // 1 ether
        value: Utils.parseEther("1.0")

    //Logging the response to the console



BigNumber { _hex: '0x651a', _isBigNumber: true }

Code Sandbox

You can test out the estimateGas method using the code sandbox below:

Use Cases

Here are some common use cases for the estimateGas method:

  • Optimizing transaction fees: Gas is the fee paid by the sender of a transaction to compensate the miners for processing it. By estimating the gas required for a transaction beforehand, developers can optimize their transaction fees by choosing the right gas price and limit.

  • Ensuring successful transactions: If a transaction runs out of gas before it is completed, it will fail and the sender will lose the gas spent on it. By estimating the required gas beforehand, developers can ensure that the transaction has enough gas to complete successfully.

  • Validating transaction parameters: When submitting a transaction, certain parameters such as the gas limit and gas price must be set correctly to avoid issues such as network congestion or excessive fees. By using estimateGas, developers can validate these parameters before submitting the transaction.

Related Methods

Here are the methods related to estimateGas:

  • getBalance: Returns the balance of a given address as of the provided block.
  • cal: Returns the result of executing the transaction, using call.