How to calculate cubic yards
cubic yards = (L × W × D in feet) ÷ 27
Example: 12 ft × 10 ft bed, 3 inches of mulch
- Convert depth to feet: 3\" ÷ 12 = 0.25 ft
- Multiply: 12 × 10 × 0.25 = 30 cubic feet
- Divide by 27: 30 ÷ 27 = 1.11 cubic yards
- Order: 1.25 yd (add ~10% for settling)
How to calculate board feet
board feet = (T × W × L) ÷ 12
T and W in inches, L in feet
A board foot is a volume unit equal to 144 cubic inches (1 ft × 1 ft × 1 inch). Standard 2×4×8 = (2 × 4 × 8) ÷ 12 = 5.33 bf. Use nominal dimensions for pricing — lumber is priced by nominal, even though actual dimensions are smaller (a '2×4' is really 1.5\" × 3.5\").
Material coverage guide (100 sq ft)
| Depth | Cubic yards | Cubic feet |
|---|---|---|
| 1" | 0.31 | 8.33 |
| 2" | 0.62 | 16.67 |
| 3" | 0.93 | 25.00 |
| 4" | 1.23 | 33.33 |
| 6" | 1.85 | 50.00 |
| 8" | 2.47 | 66.67 |
| 12" | 3.70 | 100.00 |
Common material weights (lbs per cubic yard)
| Material | Lbs / yd³ | Tons / yd³ | Notes |
|---|---|---|---|
| Concrete (mixed) | 4,050 | 2.02 | ~2 tons per cubic yard; poured foundations, slabs |
| Gravel (dry) | 2,800 | 1.40 | Road base, drainage, driveways |
| Gravel (wet) | 3,375 | 1.69 | Heavier when saturated |
| Sand (dry) | 2,700 | 1.35 | Paver base, sandbox |
| Topsoil (dry) | 2,000 | 1.00 | Landscaping, lawns |
| Topsoil (wet) | 3,240 | 1.62 | After rain; heavier to haul |
| Mulch (wood) | 500 | 0.25 | Gardens, playgrounds; covers ~100 sq ft at 3" deep |
| Compost | 1,100 | 0.55 | Garden amendment |
| Asphalt (compacted) | 3,960 | 1.98 | Pavement, driveways |
| Crushed stone | 2,700 | 1.35 | #57 stone, drainage |
Standard lumber board feet
| Nominal size | Board feet |
|---|---|
| 2×4×8 | 5.33 bf |
| 2×4×10 | 6.67 bf |
| 2×4×12 | 8.00 bf |
| 2×6×8 | 8.00 bf |
| 2×6×12 | 12.00 bf |
| 2×8×12 | 16.00 bf |
| 2×10×12 | 20.00 bf |
| 4×4×8 | 10.67 bf |
| 1×6×8 | 4.00 bf |
Frequently asked questions
How do I calculate cubic yards?
Multiply length × width × depth (all in feet), then divide by 27 (since 1 cubic yard = 27 cubic feet). Formula: cubic yards = (L × W × D in ft) ÷ 27. Example: a 12 ft × 10 ft area with 3 inches (0.25 ft) of mulch = 12 × 10 × 0.25 = 30 cubic feet ÷ 27 = 1.11 cubic yards. Order slightly more than calculated (add 5–10%) to account for settling and irregular fill.
How do I calculate board feet?
Board feet = (thickness in inches × width in inches × length in feet) ÷ 12. A standard 2×4×8 = (2 × 4 × 8) ÷ 12 = 5.33 board feet. For nominal lumber, use actual dimensions for accuracy — a '2×4' is actually 1.5" × 3.5", so real board feet = (1.5 × 3.5 × 8) ÷ 12 = 3.5 bf. Most lumber is priced by nominal board feet, not actual.
How much mulch do I need?
Measure the area in square feet, then multiply by desired depth in feet. Most gardens use 2–3 inches (0.17–0.25 ft). For a 100 sq ft bed at 3" deep: 100 × 0.25 = 25 cubic feet = 0.93 cubic yards. Order 1 cubic yard. One cubic yard of mulch covers about 100 sq ft at 3" or 150 sq ft at 2". Bagged mulch: 1 cubic yard ≈ 13.5 bags (2 cu ft each).
How much concrete do I need for a slab?
Calculate cubic yards: (length × width × thickness in ft) ÷ 27. A 10×10 ft slab at 4" (0.33 ft) thick = 10 × 10 × 0.33 ÷ 27 = 1.23 cubic yards. Concrete is sold by the cubic yard (~$125–150 delivered). Order 10% extra to account for uneven ground and spillage. For small jobs (<0.5 yd), bagged concrete is more economical: one 60 lb bag = 0.45 cu ft, so a 10×10×4" slab takes ~74 bags.
How much gravel do I need for a driveway?
For a gravel driveway, plan 4–6" of base gravel plus 2–3" of surface stone. A 12×50 ft driveway at 4" (0.33 ft) deep = 12 × 50 × 0.33 ÷ 27 = 7.4 cubic yards of base, plus 3.7 yards of surface stone. At roughly $30–50/yd for gravel, budget $450–750 for materials (plus delivery $75–200). One cubic yard weighs ~1.4 tons (wet ~1.7 tons).
What's the difference between cubic feet and cubic yards?
A cubic yard is 27 cubic feet (3 ft × 3 ft × 3 ft = 27 cu ft). Landscape and construction materials like mulch, gravel, and concrete are typically sold in cubic yards. Smaller bagged materials are often in cubic feet: 2 cu ft, 3 cu ft bags. To convert: divide cubic feet by 27 to get cubic yards, or multiply cubic yards by 27 to get cubic feet.
How many tons are in a cubic yard?
It depends on the material density. Common weights per cubic yard: concrete ~2 tons, gravel (dry) ~1.4 tons, gravel (wet) ~1.7 tons, topsoil (dry) ~1 ton, sand ~1.35 tons, mulch ~0.25 tons. A dump truck typically holds 10–15 cubic yards (20+ tons). Always ask your supplier for the specific material density — it varies by region and moisture content.
How do I measure an irregular area?
Break it into regular shapes (rectangles, triangles, circles), calculate each separately, then add them up. For L-shaped areas: calculate two rectangles. For round or curved areas: use π × r² for circles. For irregular perimeters, approximate with rectangles or measure the longest and widest dimensions and average them. Order 10–15% extra material for irregular projects.
What is a board foot?
A board foot is a unit of lumber volume equal to 144 cubic inches — 1 ft × 1 ft × 1 inch. Formula: bf = (T × W × L) ÷ 12 where T and W are in inches and L is in feet. Lumber yards price by board feet for hardwoods and premium lumber. A 12-ft-long 2×6 board = 12 board feet. Dimensional lumber (2×4s, 2×6s) is usually priced per piece, not per board foot.
How many cubic feet are in a gallon?
1 US gallon = 0.134 cubic feet (or 1 cubic foot = 7.48 gallons). 1 cubic yard = 202 gallons. These conversions matter for ponds, aquariums, and fuel storage. Metric: 1 cubic meter = 264 gallons = 1,000 liters. Our volume converter handles all these conversions instantly.