# eth\_estimateGas - Ethereum

## How to Use the eth\_estimateGas Method

### **Parameters**

TRANSACTION CALL OBJECT \[necessary]

* from: \[variable] 20 Bytes - What address are you sending transactions from.
* to: 20 Bytes - Which address should receive your transaction.
* gas: \[variable] How much gas do you need to proceed a transaction (as an integer). eth\_estimateGas doesn’t require gas at all, but with some actions you will need this parameter.
* gasPrice: \[variable] Present gasPrice for each gas you paid for as an integer.
* value: \[variable How much ETH do you send by this transaction.
* data: \[variable] Method signature and encoded parameters’ hash. Check Ethereum Contract ABI to see details.

### What you receive

QUANTITY - how much gas did you use.

### Sample

Here is a typical appliance example.

#### Call

{% tabs %}
{% tab title="Curl" %}

```bash
curl https://eth-mainnet.rpcfast.com/?api_key=<key> \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_estimateGas","params":[{see above}],"id":1}'
```

{% endtab %}
{% endtabs %}

#### Outcome

```json
{ "id":1, "jsonrpc": "2.0", "result": "0x5208" // 21000 }
```