下面我们用实例讲解怎样计算以太坊在执行交易时花费的 gas 费用。

		
> miner.start(1)
null
		
		

准备两个账号

		
> eth.getBalance(eth.accounts[3])
1000000000000000000
> eth.getBalance(eth.accounts[5])
0
		
		

开始计算 gas 费用

		
> var estimateGas = eth.estimateGas({from:eth.accounts[1], to: eth.accounts[2], value: web3.toWei(1)})
undefined
> console.log(estimateGas)
21000
undefined
> 
> var cost = estimateGas * gasPrice
undefined
> console.log(cost)
378000000000000
undefined
> web3.fromWei(cost)
"0.000378"
		
		

gas 花费 0.000378 ETH