Option notional value is calculated by multiplying the strike price of the option by the number of option contracts in the trade order and the number of shares per contract.
For example, if the strike price is $50, and you have 10 option contracts with a standard shares per contract of 100, the calculation would be:
Option Notional Value = $50 * 10 * 100 = $50,000
This represents the notional value of the underlying shares that the option contracts control.