How to calculate total minutes?

i have two time pickers.

time-in and time-out

i want it calculate total time.

kindly see the picture and resolve my issue as soon as possible

You can multiply a result with 60 and use round Math Function. 

Form Calculation - Math Function Reference

How to Perform Form Calculation Using a Widget

Here is my demo form: https://form.jotform.com/72782271679974

Feel free to test it and clone it.

Let us know if you need further assistance.