Transaction Fee = Total amount of Gas consumed by the transaction GasUsed * Price per unit of Gas in the transaction Gas Price

GasUsed: Each command in the EVM is set to the corresponding Gas consumption value, and GasUsed is the sum of the Gas consumption values of all executed commands.

Gas Price is how much ETH you are willing to pay for a unit of Gas. So the higher the Gas Price, the more ETH will be paid for each step in the transaction.