Topsoil and gravel are normally purchased by volume, while delivery limits and some supplier quotes may use weight. Start with cubic yards, then use material-specific information for the final order.

01

Calculate volume from finished dimensions

Multiply length by width to find square feet. Convert depth from inches to feet, multiply by area for cubic feet, and divide by 27 for cubic yards.

Measure irregular spaces as several rectangles or use an average width. Calculate sections separately when the planned depth changes.

  • Cubic feet = length × width × (depth in inches ÷ 12)
  • Cubic yards = cubic feet ÷ 27
  • One cubic yard covers about 108 square feet at 3 inches deep
02

Choose depth for the actual job

A topdressing layer, a raised bed, and replacement soil after excavation require very different depths. Gravel depth also depends on stone size, traffic, drainage, base preparation, and the intended use.

The calculator reports the volume you describe; it does not prescribe a construction section or planting depth. Use project specifications or local professional guidance for structural and drainage work.

03

Allow for settling and compaction deliberately

Loose topsoil can settle after placement, while gravel bases are commonly compacted. The amount of change depends on material grading, moisture, placement method, and the existing surface.

Avoid applying one universal adjustment to every material. Ask the supplier whether quoted volume is loose, screened, compacted, or measured by loader bucket, and add an allowance that matches the job.

04

Do not convert volume to weight with a generic constant

Gravel density varies with rock type, particle size, void space, and moisture. Soil weight also changes substantially with composition and water content.

Use the supplier's tons-per-yard figure for the exact product. Confirm delivery-truck capacity, minimum quantities, access, dump location, and whether multiple loads will be required.

Bottom line

Calculate cubic yards from area and finished depth, then confirm density, compaction, and delivery rules with the material supplier.

Frequently asked questions

How much area does one cubic yard cover at three inches deep?

One cubic yard covers about 108 square feet at a uniform depth of three inches. Irregular grades, settling, and compaction can change the delivered amount needed.

Can cubic yards be converted to tons with one standard number?

No. Weight varies with material type, grading, void space, and moisture. Use the supplier's product-specific tons-per-yard figure.

Sources and further reading

Sources support the methods and practical guidance above. Product specifications and local requirements should take priority for a specific project.

USDA Natural Resources Conservation Service: Soil Health Official background on soil properties and management considerations. National Institute of Standards and Technology: Volume Official measurement guidance on volume and cubic units.