How to estimate the cost for deploying smart contract on mainnet

Question

I want to deploy a contract on mainnet, however I'm not able to figure out the gas estimate cost to deploy the contract there.
Can somebody tell me the gas price and max gas price for an ideal contract.
Also, is it possible to make around 10 billion tokens on main net. 

Answer 1

Since you have already deployed the contract on Ropsten network, you must have already managed to use a sensible equivalent gas amount.

estimateGas function will give you the estimate amount of gas you need to execute the contract.

Comments

I deployed on ropsten and it was about $6USD workth of eth, then the main net wanted closer to $200 usd worth of eth. Am I doing something wrong? Or are the prices for deployment just completely different? If different, how does one estimate other than clicking deploy button on mainnet and seeing the estimate, then canceling?

Answer 2

You should test your deployment process on private network or test network throughly before trying mainnet. I see you have tested yours on Ropsten, but I would suggest you to test preferably on Rinkeby because in Ropsten block gas limit is too low.

In my experience gasPrice setting in truffle.js is effective. I have successfully deployed my contracts using the following syntax:

geth_mainnet: {
      host: "127.0.0.1",
      port: 8545, // geth-mainnet
      network_id: "1",
      gasPrice: 2000000000, // 2 GWei
      from: "0x...your-address-goes-here..."
    }

Make sure your account has enough funds not only for your smartcontract deployment, but also for deployment of truffle's Migration contract and calls to that contract.

Hope it helps!

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Thanks.

Answer 3

To estimate the cost for deployment, I use functions of Web3. This is what you have to do:

1. Get the gas price (in wei) using the web3.eth.getGasPrice function.

2. Then use the estimateGas function to get the gas estimation for a function (with the parameters passed)

3. Gas cost estimation = number of gas * gas price

For example

var TestContract = artifacts.require("./Test.sol");
...

...

...

// getGasPrice returns the gas price on the current network
TestContract.web3.eth.getGasPrice(function(error, result){
    var gasPrice = Number(result);
    console.log("Gas Price is " + gasPrice + " wei"); // "10000000000000"

    // Get Contract instance
    TestContract.deployed().then(function(instance) {

        // Use the keyword 'estimateGas' after the function name to get the gas estimation for this particular function
        return instance.giveAwayDividend.estimateGas(1);

    }).then(function(result) {
        var gas = Number(result);

        console.log("gas estimation = " + gas + " units");
        console.log("gas cost estimation = " + (gas * gasPrice) + " wei");
        console.log("gas cost estimation = " + TestContract.web3.fromWei((gas * gasPrice), 'ether') + " ether");
    });
});

Output:

Gas Price is 20000000000 wei 

gas estimation = 26794 units 

gas cost estimation = 535880000000000 wei 

gas cost estimation = 0.00053588 ether

Comments

The sentence "TestContract.web3.eth.getGasPrice(function(error, result)" makes me confused. Why add "TestContract" before "web3.eth.getGasPrice", instead of directly using"web3.eth.getGasPrice"? Isn't  "web3.eth.getGasPrice" a complete method, why should we add a contract object before it?

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Hey @XHQ.

Yes, you can use web3.eth.getGasPrice directly. The function is just used to get different conversions of the gas price. Just to make it more descriptive. 

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I get it, thanks!

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Hi, I have a very small problem but it makes me very confused. https://www.edureka.co/community/42803/solidity-function-placed-before-brace-when-define-function  Could you please answer it? It will be really kind of you.

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Hi, I have answered, please check.

Answer 4

You can use testrpc for this. When you use testroc and deploy a smart contract, you can see the cost for deploying the smart contract on the terminal running testrpc.

Comments

Hi @Giri. When I use this approach, the cost is displayed after I deploy. I want to know the cost before deployment. How can I do this in testrpc?

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I don't think testrpc allows this feature. You will have to use truffle of gas estimate function as mentioned in other answers

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The question was specifically asked for mainnet. Testrpc is used only for development and not actually deployment.