Assuming you’re using Geth:
1. Connect to your geth node.
If you’re using a local node, you can use the IPC endpoint. For example:.
geth attach ipc:/home/ethereum/.ethereum/geth.ipc
If you’re using an infura node, you’ll need to use the RPC endpoint. For example:
geth attach https://mainnet.infura.io/v3/YOUR-PROJECT-ID
2. Use the eth_getTransactionByHash RPC call to get information about a particular transaction. For example:
> eth_getTransactionByHash “0x88df016429689c079f3b2f6ad39fa2c258a2529ef7e6dc77054e7bf099667ee”
{
blockHash: “0x33db5ae7419d569f616b58fbc55ec296bc0df9d3147383a4812fb94d0912765”,
blockNumber: “0x388372”,
from: “0x4e83362442a28205cecd5a72ee861a1f1b78070a”, // This is the sender’s address
gas: “0x15f90”, // This is the amount of gas used by the transaction
gasPrice: “0x4a817c800”, // This is the gas price in wei (10^-9 ETH)
hash: “0x88df016429689c079f3b2f6ad39fa2c258a2529ef7e6dc77054e7bf099667ee”, // This is the transaction hash
input: “0xa9059cbb0000000000000000000000004e83362442a28205cecd5a72ee861a1f1b78070a0000000000000000000000000000000000000000000000000000000000002710″, // This is the data field of the transaction, which in this case is a contract call (encoded as ABI) to the ERC20 transfer function transferring 2,712 tokens from sender to recipient with address 0x4E83362442A28205CECd5A72EE861A1F1B78070A. Note that this data field can also be empty for simple value transfers between addresses. To decode this data field, you can use an ABI decoder such as https://abi.hashex.org/ or https://toolkit.chainstack.com/decode-transaction-data, or if you’re using Geth you can use the admin_eth_abiDecodeLog RPC call (see https://github.com/ethereum/go-ethereum/wiki/Management-APIs#admin_eth_abidecodelog).
nonce”: “0x11″, // This is the nonce of the sending account, used to prevent replay attacks (https://en.wikipedia.org/wiki/Replay_attack). To get this value, you can use the eth_getTransactionCount RPC call (https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_gettransactioncount). r”: “0xb59d55bfa4ef75554cd08ae867107dd0507ca55ddea349fb529462ba1607fe66”, // This is one of two values used to verify that the transaction was signed by the sender’s private key corresponding to their address (the other value being v). To verify that a transaction was signed by a particular address, you can use https://etherscan.io/, which will show you the signer’s address next to the “From” field if it was able to verify the signature, or you can use a tool such as https://github.com/kvhnuke/etherwallet/tree/mercury#online-signer to verify signatures yourself s”: “0x36b93de5502144b13ffda50cb968785fd3379783067c3196836aa49254355ea3″, // see r description above v”: “0x25″, // see r description above value”: “0xde08884c0751f24bebd58bb46089ec881810218e160b6f927ec8ede5460a6552” // This is the value being transferred in wei from sender to recipient }.
As you can see from this example transaction, there are several fields which are important in understanding how much gas was used by a transaction:
gas – This is the amount of gas used by this transaction. Note that this is not necessarily equal to the amount of gas consumed by all of the computations performed by this transaction, since unused gas is refunded to the sender at the end of execution; rather, it’s equal to gas consumed – refunded gas .
In this example, we can see that 21000 – 24406 = 1594gas was consumed by this transaction (although note that refunds are capped at half of total gas used).
gasPrice – This is the price of each unit of gas used in wei . In this example, we can see that each unit of gas costs 4000000000 wei , or 0 .
04 ETH .
value – This is the value being transferred in wei from sender to recipient . In this case, we can see that 1 ETH is being sent from 0 x4E8 3362442A28 205CEC d5A72EE86 1A 1F 1B78070A to 0 xde08884 c075 1 F24BEBD58 BB46089EC 881810218E 160 B6F927EC 8EDE5460 A6552 .
To calculate the total cost of a transaction in ETH , simply multiply gasUsed * gasPrice . In our example above, this would be 1594 * 0 .
04 = 0 . 06376 ETH .
Alternatively, if you’re using Parity , you can use their traceTransaction API call instead (see https://wiki.parity.