I just had a new patio poured in back of the house and I am surrounding it with 1 1/2 in river rock. I have an area approximately 24 x 15, and I would like it to be about 4 in deep. How many tons of rock should I order?

IT eill take 4 1/2 yards of rock , I can't think what it weighs per yard right now ,all you need to tell them is how many yards you need;;;;