[AccessD] Programming

Hi Group

A general programming question.  Would you ever store calculated values
in a table.  My example is this...

I have a Timesheetline table recording jobstart, jobend times/dates etc.
Do I store jobtotalhours in the table and do I store
Client charge and EmployeePaid amounts.  I would not normally store
calculated values in a table but as these calculations are quite complex
(different charge rates, time periods e.g std and overtime etc)
I thought that once calculated (at the point of data entry) why not
store these values in table (may improved report speed/programming).
Alternativley, isn't this what computers are for ie carrying out complex
calculations so why store value, when it comes to reporting on or
displaying etc simply recaculate.   My leaning now is not to store these
values. Any thoughts?

Richard