Bulk Material Volume Calculator
Estimate the cubic yards of soil, mulch, or gravel needed for your project.
How to Calculate Bulk Material Needs
When planning a landscaping project, calculating the correct amount of bulk material is essential to avoid multiple trips to the yard or overspending. Bulk materials like topsoil, mulch, and decorative stone are typically sold by the cubic yard.
The mathematical formula used by this calculator is:
(Length in feet × Width in feet × (Depth in inches / 12)) / 27 = Cubic Yards
Why Depth Matters
The depth of your material significantly changes the volume needed. For example, 3 inches of mulch is standard for weed suppression, while 4 to 6 inches of gravel may be required for a stable driveway base. Always measure the depth in inches and convert it to feet (by dividing by 12) before multiplying by the area.
If you have a garden bed that is 30 feet long and 5 feet wide, and you want to apply mulch 3 inches deep:
1. Area: 30 ft × 5 ft = 150 sq. ft.
2. Depth: 3 inches ÷ 12 = 0.25 ft.
3. Volume: 150 sq. ft. × 0.25 ft = 37.5 cubic feet.
4. Conversion: 37.5 / 27 = 1.39 Cubic Yards.
Material Density and Compaction
If you are ordering "compactible" materials like crushed limestone or road base, it is wise to add a 10-20% buffer. These materials settle and compress when flattened or walked upon. For mulch or loose topsoil, a 5% buffer is usually sufficient to account for uneven grades in the soil.
Common Conversions for Landscapers
- 1 Cubic Yard: Covers 324 square feet at 1 inch deep.
- 1 Cubic Yard: Covers 108 square feet at 3 inches deep.
- 1 Cubic Yard: Covers 81 square feet at 4 inches deep.
- Standard Mulch Bag: Usually 2 cubic feet (13.5 bags per yard).