Landscape material weight — one cubic yard is 0.65 tons of lava rock but 1.5 tons of riprap

Cubic yards and tons don’t line up the same way for every material — planning densities run from ~1,300 lb/yd³ (lava rock) to ~3,000 lb/yd³ (riprap). So one cubic yard is 0.65 tons of lava rock but 1.5 tons of riprap, and a ton of a light material covers far more ground. Compare prices per cubic yard (volume), not per ton.

What this diagram shows

A bar chart showing that one cubic yard of different landscape materials weighs very different amounts, because their planning densities span roughly two to one. Each bar is one cubic yard, 27 cubic feet, and its height is the weight per cubic yard. Lava rock is about 1,300 pounds per cubic yard, roughly 0.65 tons — half the weight of the rest. Topsoil is about 2,200 pounds, 1.10 tons. River rock is about 2,600 pounds, 1.30 tons. Crushed stone is about 2,700 pounds, 1.35 tons. Riprap is about 3,000 pounds, 1.50 tons and the heaviest. Because a ton of a light material fills far more volume than a ton of a heavy one, a ton of lava rock covers roughly twice the area of a ton of crushed stone. The takeaway is to compare prices per cubic yard, the volume, rather than per ton when materials differ.