Is there a formula for calculating the difference in minutes or hours between two times?

Question

Is there a formula for Is there a formula for calculating the difference in minutes or hours between two times in two columns?

In my spreadsheet I have the following two columns called start time and end time. In those fields I enter the time in hours and minutes:

start   end
6:45    7:45

I'd like a third column that has the total difference between them like so:

Is there a formula that will do this? This is for Google Sheets but IIUC formulas from Excel may work in Google sheets???

UPDATE:
Using the formula suggested, =(B1-C1), it's giving me the correct hours and minutes (edit - actually it does work see update 2).

Using the other suggestion, =(B1-C1)*24, I'm not getting the following value:

In the second case, if I change the time field to a number it changes:

Before (formatted as automatic):

After (formatted as Number):

Here's the menu items:

UPDATE 2:
The formula does work. To get it to work I needed to format the formula cell as a number, not the time cells.

Answer 1

Try this method:

1. Format cells to Number

2. Enter the formula:

   =(B1-A1)*24