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eth_estimateGas

Estimate gas needed for execution of given contract
web3.eth.estimateGas(callObject [, callback])

Parameters

  1. 1.
    A transaction object.
  2. 2.
    (optional) Optional callback, returns an error object as first parameter and the result as second.

Returns

the used gas for the simulated call/transaction.

Example

web3.eth.estimateGas({
from : account1,
to : account2
}).then(console.log);
> 21000