How to calculate the Profit

Hi All,

I find the property Profit, but don't know how the Profit is calculated.
I look in the models but only find decimal Profit {get; set;}
I need to know what is the field in dbo.Order that corresponds to Profit property or what fields are used for the calculation.
I am updating and refining my payment plugin, I want that all the payment status, order status, Order Totals and so on be updated on the customer payment conclusion.

Best regards.