Calculating hours worked in excel

I am trying to make a spreadsheet in excel to calculate my hours worked for example if i put my start time in cell A1 and my end time in cell B1 and my lunch in C1 how do i get the total hours worked in D1? is there a formula that does that?
This is a copy of my spreadsheet
Week 1
Day In Out Break Total OT
Monday 8:30 5:00 1:00
Tuesday
Wednesday
Thursday
Friday
Total