Article — Cubic Yard Calculator
Cubic yard calculator: volume and weight for any material
A cubic yard is a 3 ft × 3 ft × 3 ft cube — exactly 27 cubic feet, or 0.7646 cubic metres. To find cubic yards, multiply length × width × depth in feet and divide by 27. With depth in inches, divide by 324. A 10 × 12 ft area at 4 inches deep is 1.48 cubic yards. Weight depends on the material: 1 yd³ of fresh concrete is 4,050 lb (2.03 short tons), 1 yd³ of dry gravel is 2,835 lb (1.42 tons), and 1 yd³ of wood mulch is only 590 lb (0.30 tons).
The cubic yard is the standard US unit for buying bulk material. Concrete trucks, gravel dump trucks, and topsoil deliveries are all priced by the yard. One mixer truck typically holds 8 to 12 yd³; one dump truck holds 10 to 15 yd³. Knowing how much you need before calling the supplier avoids both shortages and surplus charges.
The cubic yard formula
Every cubic yard calculation reduces to length × width × depth followed by a unit conversion. The conversion factor changes depending on whether depth is in feet or inches.
yd³ = (L_ft × W_ft × D_ft) / 27 all feetyd³ = (L_ft × W_ft × D_in) / 324 depth in inches1 yd³ = 27 ft³ = 0.7646 m³ conversionstons = yd³ × density material weightcoverage_ft² = 324 / D_in per cubic yardDepth in inches and length-width in feet is the practical default. Most material layers are thin — 4 to 6 inches for concrete, 2 to 4 inches for mulch, 1 to 2 inches for paver bedding — while horizontal areas span tens of feet. Converting everything to feet means writing 0.333 ft for 4 inches, which invites typos.
Cubic yard, cubic foot, cubic metre
Three units cover almost every bulk material order. Cubic yard dominates US construction. Cubic foot is used for bagged products and small quantities. Cubic metre is the rest of the world’s standard.
Converting between units is straightforward: 1 yd³ = 27 ft³ = 0.7646 m³ = 201.97 US gallons (liquid). The most common mistake is reporting 27 cubic feet and then ordering 27 cubic yards — a factor of 27 error that can pile up thousands of dollars of surplus material on a small lot.
Cubic yards of concrete
Concrete is the most common cubic-yard purchase. A 4-inch slab over a 20 × 20 ft area needs (20 × 20 × 4) ÷ 324 = 4.94 cubic yards. Add 5 to 10% for spill and edge loss, so order 5.2 to 5.4 yd³. Ready-mix concrete trucks deliver in full and partial yards; the typical pricing is $140 to $200 per yard plus delivery and a minimum charge for short loads.
The US Geological Survey reports that the US produces roughly 95 million cubic yards of ready-mix concrete every year, valued at around $40 billion. The figure undercounts the total because it excludes site-mixed concrete from bags. Concrete is the second-most consumed substance on the planet after water, and most of it leaves the plant in cubic-yard-denominated trucks.
Cubic yards of gravel and sand
Gravel and sand orders look similar to concrete in math but with different densities. Dry gravel weighs 1.42 short tons per cubic yard. A 50 ft × 12 ft driveway at 4 inches needs (50 × 12 × 4) ÷ 324 = 7.41 yd³, or about 10.5 tons. Order at the high end of any calculation because both gravel and sand compact 10 to 15% under load in the first year.
- Concrete fresh = 4,050 lb/yd³ (2.03 t)
- Sand dry = 3,000 lb/yd³ (1.5 t)
- Gravel dry = 2,835 lb/yd³ (1.42 t)
- Topsoil = 2,200 lb/yd³ (1.10 t)
- Compost = 1,200 lb/yd³ (0.60 t)
- Mulch wood = 590 lb/yd³ (0.30 t)
Cubic yards of mulch and soil
Mulch is the lightest common material, at 590 lb per cubic yard. A 200 ft² bed at 3 inches deep needs (200 × 3) ÷ 324 = 1.85 cubic yards, or about 1,090 lb. That fits in 17 bags of 2 cubic feet, or a half-truck bulk delivery. Bulk mulch costs $20 to $40 per yard; bagged costs $4 to $8 per 2-cu-ft bag, working out to $54 to $108 per yard equivalent.
For mulch beds the breakeven between bagged and bulk is around 2 cubic yards. Below that, bagged is cheaper after counting delivery fees and handling. Above 2 yards, the bulk price wins decisively. Spread bulk mulch within a week of delivery — wet piles heat up and can self-combust in extreme cases, though smoldering is more common than open flame.
Cubic yard coverage by depth
Coverage is the area one cubic yard fills at a given depth. The formula is 324 ÷ depth in inches. A cubic yard covers 324 ft² at 1 in deep, 81 ft² at 4 in, or 54 ft² at 6 in. Depth varies by application: 3 in for mulch beds, 4 to 6 in for driveway gravel and concrete slabs, 1 to 2 in for paver bedding sand, 2 to 4 in for top dressing soil.
Common cubic yard mistakes
Two errors dominate. The first is unit confusion: reporting volume in cubic feet and then ordering in cubic yards (factor of 27 off). The second is mixing depth units with horizontal units — depth in inches with length-width in feet means dividing by 324, not 27.
A 100 ft² area at 4 inches of concrete is 33 cubic feet. That is 33 ÷ 27 = 1.23 cubic yards. Reporting 33 and ordering 33 produces 27 times too much material. The error has cost first-time owner-builders thousands of dollars when ordering ready-mix. Always sanity-check by converting both ways before placing the order.
Bulk vs bagged delivery
Bagged material is convenient but expensive per cubic yard. Bulk delivery is cheaper but requires somewhere to dump 5 to 15 cubic yards of material at once. The breakeven point depends on material price: for mulch and topsoil, bulk wins above 2 cubic yards. For concrete, bulk wins immediately because ready-mix trucks are the only realistic source of any meaningful slab volume.
One subtlety: delivery distance changes the math. Most suppliers include 10 to 20 miles in the base price, then charge $2 to $5 per mile beyond. For a rural site 40 miles from the quarry, delivery can add $100 to $200 to a bulk order, narrowing the gap with bagged material substantially.