Creating a simple timesheet in Google Sheets

Question

In a nutshell I'm trying to build a custom timesheet that automatically calculates hourly pay and so forth and I'm stuck on the following problem.

How do I make Google Sheets calculate the simple decimal of hours worked? I want to enter a start and end time and produce an output like the following.

   In     Out   Total
---------------------------
 |7:30 | 12:00 | 4.5 |
---------------------------

Answer 1

Google Spreadsheets stores time/date in multiples of days. (Or, more accurately, in a number since an "epoch" date.)

So, =B2-A2 in cell C2 will give you 0.1875, assuming you have the cell formatted as a number and not a date.

Changing that to =(B2-A2)*24 will give you the value in hours, or 4.5.