Calculate the difference between two time fields.

I have two time fields that I am trying to calculate the difference between. 

Time in
Time out

My calculation field is [Time Out]-[Time In]

It seemed simple enough, however, I have run into some issues when it comes to midnight. 

If I clock in at 5 pm and clock out at 12 am the calculation should be 7 hours. However, it is returning a value of -17 hours. 

Is there a way to get this to calculate properly. 

I should mention that I would also want it to work if I clock in at 12 am and out at 2 pm it should give me a value of 14 hours. 

Any help would be greatly appreciated.