Multiply the total number of tons by 2,000 to convert the unit of measurement from tons to pounds. Therefore, if you have four tons of sand gravel, it would equate to 8,000 pounds of sand gravel.
Record one of the following densities depending on whether you are measuring wet or dry sand gravel. When dry, sand gravel has a density of 2,781 pounds per cubic yard. When wet, the density increases to 3,405 pounds per cubic yard.
Divide the number of pounds by the density of the sand gravel. This number is the converted unit of measurement in cubic yards. For example, if you have 8,000 pounds of dry sand gravel, you would divide 8,000 (the number of pounds) by 2,781 (the standard density for dry sand gravel). The result, 2.876, is your amount of sand gravel in cubic yards.