How to Calculate Cubic Yards for Gravel, Mulch and Concrete

What is a cubic yard?

A cubic yard is a volume measuring one yard long, one yard wide and one yard high. Because one yard equals three feet, one cubic yard contains 27 cubic feet.

1 cubic yard = 27 cubic feet

Cubic yard formula

When length, width and depth are all measured in feet, multiply them to find cubic feet, then divide by 27.

Cubic yards = Length(ft) × Width(ft) × Depth(ft) ÷ 27

When depth is measured in inches

Depth for mulch, gravel and similar materials is often specified in inches. Divide the depth by 12 to convert it to feet first.

Depth in feet = Depth in inches ÷ 12

Example: gravel area

For an area 30 feet long, 12 feet wide and 4 inches deep, convert 4 inches to approximately 0.333 feet. The volume is about 120 cubic feet, or approximately 4.44 cubic yards.

Why material quantities can differ from calculated volume

Compaction can reduce final material depth.
Loose material can settle after placement.
Excavated surfaces are rarely perfectly level.
Different materials have different densities and moisture content.

Cubic yards vs tons

Cubic yards measure volume while tons measure weight. Converting between them requires the density of the specific material. Gravel, soil, mulch and concrete do not share one universal conversion factor.

Ordering bulk materials

Supplier density, compaction assumptions and minimum delivery quantities can affect the amount you should order. Use the calculator as a planning estimate and confirm material-specific details with the supplier.