Calculating Time to Run the Pump

How would I figure out how much time it would take for the pump to recirculate the full volume of the pool? (I am math impaired, so please help me out!!)I'm guessing I need to know the total volume of the pool to start with...but am lost at that point!! Generally we run the pump about 12hrs per day and have been lucky to keep nice and clear, but with rising energy costs, if we can cut it down a bit, it would be a bonus.
So far all I know is the pool is IG, 16X32 vinyl, 3ft shallow end, 8 foot deep end with sloped sides......2 return jets, one skimmer...I guess also I need to go out and find out more info on the pump....thanks in advance for any help.(I have a calculator handy!!!)

Need more info from you....
16' x 32' freeform? rectangle?
3' to 8' depth. Do you have a 5' break?
Need the above info to figure out how many gallons.
What size / brand /model pump do you have? (need this to find out the GPM)

Need the size of the plumbing too.

As a cheep and 'no math required' way of doing this, just cut back the pump run time by an hour every few days and see how the pool looks. When it 'turns' nasty, go back to the previous run-time (after treating the 'nasty'), this will save you a bunch of computations which may or may not be right.