eth_estimateGas

Estimates the amount of gas required to execute a transaction.

Estimates the amount of gas required to execute a transaction. The estimate may be higher than the gas actually used at execution time.

Parameters

transactionObject · object · required

The transaction object to estimate gas for.

Show Transaction object fields

from · string

The 20-byte address the transaction is sent from. Optional.

to · string

The 20-byte destination address. Required for contract calls; omit for contract deployments.

gas · string

Gas limit for the estimate. Optional.

gasPrice · string

Gas price in wei for legacy transactions. Optional.

maxFeePerGas · string

EIP-1559 maximum total fee per gas. Optional.

maxPriorityFeePerGas · string

EIP-1559 maximum priority fee per gas. Optional.

value · string

ETH value to send with the transaction in wei. Optional.

data · string

ABI-encoded call data. Optional.

blockParameter · string

Optional block to estimate against. Defaults to latest.

Returns

result · string

The estimated gas amount as a hexadecimal integer.

Flashblocks Behavior

On a Flashblocks-aware endpoint, use "pending" as the block parameter to query preconfirmed state — data available up to 200ms before the next full block is sealed.

Estimates gas against the latest preconfirmed Flashblock state. Use "pending" to get an estimate based on the most current state, reducing the chance of reverts due to stale state.

cURL (preconfirmed state)

curl https://mainnet-preconf.base.org \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_estimateGas","params":[{"from":"0xd3CdA913deB6f4967b2Ef66ae97DE114a83bcc01","to":"0x4200000000000000000000000000000000000006","value":"0x2c68af0bb14000"},"pending"],"id":1}'

Example

Request

{
  "jsonrpc": "2.0",
  "method": "eth_estimateGas",
  "params": [
    {
      "from": "0xd3CdA913deB6f4967b2Ef66ae97DE114a83bcc01",
      "to": "0x4200000000000000000000000000000000000006",
      "value": "0x2c68af0bb14000"
    }
  ],
  "id": 1
}

Errors

Code	Message	Description
-32000	execution reverted	The transaction would revert. The error data may contain a revert reason.