Total calculation based on unit price and UDF field values

Hi All,

This is for a construction related company. Please find attached screen shot for details.

My scenario is when we are creating sales order my client wants to calculate the total amount based on unit price towards the UDF fields defined. For example user will give the unit price per sqft in Unit price ie 2800 as per screen shot column and constructed area in Sqft in he will enter the area like cons area in sqft =1500. So this 1500 need to calculate with unit price and will display in total. So in Total field it should show like 2800*1500= result. Like wise other amount values in udf needs to be calculated and displayed in total field .

Is this possible in SAP B1. Please help me with your valuable suggestions.