Calls Per Hour

I am a supervisor in a call center and I have an excel spread sheet for phone agents when an agent comes to work in the morning they log into there phone and I have a program that records the time they are in the phone and how many calls they take. When they go on break or lunch or step away from there desk they go into what is called AUX time. At the end of the day I run a report and it shows me the total length they were logged in lets say 9 hours 2 minutes 57 seconds and on the report it shows it as 09:02:57 . Then it breaks it down into ACD (which is the time they were actually on the phone) and AUX time so lets say they were in AUX time 2 hours 14 minutes and 28 seconds that is displayed in the same format of 02:14:28. So at the end of the day I input that into an excel spread sheet I have created that automatically tells me how long they were on the phone taking calls so in this case they would have been on the phone form 7 hours 28 minutes 29 seconds7:28:29. I then have to manully figure up that time into a decimal number so I have to figure up that they were on the phone for 7.5 hours I then have to manually figure up the calls per hour average so on the report it shows me how many calls they did for the day so if they took 56 calls for the day I take 56/7.5=7.5 calls per hour because we round to the 10th. What I want to know is if there is anything I can do to have the time automatically converted into decimal and then when I input the calls if it will automatically figure the calls per hour.