A cubic yard of gravel weighs between 2,200 and 2,600 pounds, depending on the type of gravel selected. Washed gravel and limestone base tend to be heavier, while landscape gravel and washed limestone are the lightest.
In most cases, a cubic yard of gravel provides enough material to cover a 100-square-foot area with 3 inches of gravel. Some material compacts more than others, so the exact coverage is sometimes less.
In some applications, lava rock is an acceptable substitute for gravel. This porous material is lighter than normal gravel, weighing between 1,000 and 1,300 pounds per cubic yard. Lava rock is easier to haul and less work to spread than ordinary gravel.