over-estimated cubic feet to ton?

I've called two different companies, both of whom claim it will take 4-5 tons of sand to fill a hole 12' x 12' x 5". I don't know if the sand is wet or dry, but I'm assuming it is damp, what with weather in Missouri.

Is this an accurate estimate? Elsewhere, we've calculated roughly 76 cubic feet of sand for fill and jointing of pavers. I know that's not even close to what these guys are estimating. Can you help?

Thanks,

Lisa Marie