Cubic Yard Conversion Guide
A cubic yard (yd³) is the universal volume unit for bulk building and landscaping materials across North America—including ready-mix concrete, gravel, fill dirt, mulch, and sand. Master the underlying geometry, mathematical conversion formulas, and weight correlations below.
Core Principle: Why We Divide by 27
One linear yard equals exactly 3 linear feet. When expanded into three-dimensional volume, a cubic yard measures 3 feet long by 3 feet wide by 3 feet tall: 3 ft × 3 ft × 3 ft = 27 cubic feet. Therefore, whenever job dimensions are calculated in cubic feet, you must always divide by 27 to convert to cubic yards.
Primary Formulas by Geometric Shape
Because structural plans and landscape stakes specify horizontal lengths in feet while depth or thickness is measured in inches, field formulas require unit synchronization before volume calculations.
1. Rectangular Slabs & Footings
L × W × HFor patios, garage floors, walkways, driveways, garden beds, and foundation grade beams:
Worked Example: A slab 20 ft long by 15 ft wide at 4 inches thick:
20 × 15 × (4 ÷ 12) = 300 × 0.3333 = 100 ft³
100 ft³ ÷ 27 = 3.70 cubic yards.
2. Cylinders, Sonotubes & Post Holes
π × r² × HFor deck footings, round columns, drilled caissons, and fence post holes:
Worked Example: A 12-inch diameter Sonotube (1.0 ft) drilled 4 feet deep:
Radius = 0.5 ft. Area = 3.14159 × (0.5)² = 0.7854 sq ft.
Volume = 0.7854 × 4 ft = 3.14 ft³ ÷ 27 = 0.116 yd³ per post hole.
Quick Reference Conversion Cheatsheet
Cross-reference cubic yards against cubic feet, cubic inches, metric cubic meters, 80-lb pre-mix concrete bags, and standard crushed gravel tonnage.
| Cubic Yards (yd³) | Cubic Feet (ft³) | Cubic Inches (in³) | Cubic Meters (m³) | 80 lb Concrete Bags | Gravel Est. Weight |
|---|---|---|---|---|---|
| 0.25 yd³ | 6.75 ft³ | 11,664 in³ | 0.19 m³ | 12 bags | 0.35 tons |
| 0.50 yd³ | 13.50 ft³ | 23,328 in³ | 0.38 m³ | 23 bags | 0.70 tons |
| 0.75 yd³ | 20.25 ft³ | 34,992 in³ | 0.57 m³ | 34 bags | 1.05 tons |
| 1.00 yd³ | 27.00 ft³ | 46,656 in³ | 0.76 m³ | 45 bags | 1.40 tons |
| 1.50 yd³ | 40.50 ft³ | 69,984 in³ | 1.15 m³ | 68 bags | 2.10 tons |
| 2.00 yd³ | 54.00 ft³ | 93,312 in³ | 1.53 m³ | 90 bags | 2.80 tons |
| 3.00 yd³ | 81.00 ft³ | 139,968 in³ | 2.29 m³ | 135 bags | 4.20 tons |
| 4.00 yd³ | 108.00 ft³ | 186,624 in³ | 3.06 m³ | 180 bags | 5.60 tons |
| 5.00 yd³ | 135.00 ft³ | 233,280 in³ | 3.82 m³ | 225 bags | 7.00 tons |
| 10.00 yd³ | 270.00 ft³ | 466,560 in³ | 7.65 m³ | 450 bags | 14.00 tons |
Material Weight Equivalents (Pounds & Tons per Cubic Yard)
Volume alone does not dictate hauling capacity. You must account for material density when loading pickup trucks or ordering dump trucks:
Standard wet mix density is 145 to 150 lbs/ft³.
DGA and #57 stone density averages ~100-105 lbs/ft³.
Dry loose soil is ~75 lbs/ft³; damp soil reaches 90 lbs/ft³.
One pickup truck bed easily carries 2 to 2.5 yards of dry mulch.