easy formula question

[j lunis]

How do I perform math calculations on time increments?

For example, 7 * 20 minutes = 2 hours, 20 minutes (2:20),
and 3 hours - 1 hour ten minutes = 1 hour, 50 minutes (1:50).

I know how to format cells to show time but I can't find how to
calculate an answer that shows up as time.

 

[krcowen]

The time is actually a fraction of a day. Replace 20 (minutes) with
20/60/24, since there are 60 minutes in an hour and 24 hours in a
day. 3 x 20/60/24 should give 1:00 when formatted as time.

Good luck

Ken
Norfolk, Va

 

[T. Valko]

If you have true Excel time values entered then it's just straight math:

A1 = 0:20 (h:mm format)

=A1*7 (format as h:mm)

A2 = 3:00 (h:mm format)
B2 = 1:10 (h:mm format)

=A2-B2 (format as h:mm)