How to use the cubic yard calculator
- Choose the shape of the area: rectangle, circle, triangle, or a total area you already know.
- Enter length and width in feet (or meters) and the depth in inches (or centimeters). For deep fills, remember 12 inches = 1 foot, so 2 ft deep = 24 in.
- Pick a material if you also want the weight. Cubic yards do not depend on the material; tons do.
- Add a little extra. 5% covers uneven ground for most jobs; use 10% for mulch or soil that will settle.
The cubic yard formula
Cubic feet = length (ft) × width (ft) × depth (ft)
Cubic yards = cubic feet ÷ 27
Because depth is usually measured in inches, the shortcut is length × width × depth (in) ÷ 324, since 12 × 27 = 324. In metric, 1 cubic yard = 0.7646 m³ and 1 m³ = 1.308 yd³ (exact definitions from NIST Handbook 44's unit tables).
How much area does one cubic yard cover?
Divide 324 by the depth in inches to get square feet covered by one cubic yard:
- 1 inch deep: 324 sq ft
- 2 inches: 162 sq ft
- 3 inches: 108 sq ft
- 4 inches: 81 sq ft
- 6 inches: 54 sq ft
- 12 inches: 27 sq ft
Worked example
A flower bed is 12 ft × 10 ft and you want 3 inches of material, plus 5% extra.
- Area: 12 × 10 = 120 sq ft
- Volume: 120 × 3 ÷ 12 = 30 cu ft; with 5% = 31.5 cu ft
- Cubic yards: 31.5 ÷ 27 = 1.17 yd³
- As topsoil at 78 lb/ft³: 2,457 lb ≈ 1.23 tons
- As 2 cu ft mulch bags: 31.5 ÷ 2 = 16 bags
Weight of a cubic yard by material
Suppliers sell soil and mulch by the yard but stone and sand by the ton, so the weight matters. Typical loose, dry figures from The Engineering ToolBox density tables:
- Topsoil / loam, dry: 78 lb/ft³ ≈ 2,100 lb (1.05 tons) per yard
- Sand, dry: 100 lb/ft³ ≈ 2,700 lb (1.35 tons) per yard
- Gravel, dry: 105 lb/ft³ ≈ 2,835 lb (1.42 tons) per yard
- Concrete, wet: about 150 lb/ft³ ≈ 4,050 lb (2 tons) per yard
- Wood mulch: very variable with moisture, often 400–800 lb per yard
Moisture can add 15–20% to soil and sand weight, which matters for small trailers and pickup payloads.
Bags per cubic yard
One cubic yard equals 13.5 bags of 2 cu ft mulch, 27 bags of 1 cu ft, 36 bags of 0.75 cu ft, or 54 bags of 0.5 cu ft. For concrete, an 80 lb bag of QUIKRETE Concrete Mix yields about 0.6 cu ft according to the manufacturer, so a full yard takes 45 bags — at that point, ready-mix delivery is usually easier.
Tips
- Measure depth in several places and use the average; one shallow corner can skew the order.
- Most bulk yards sell in half- or whole-yard steps. Round up, not down.
- For irregular beds, split them into rectangles and circles, total the areas, and use I know the area.
Frequently asked questions
How do I calculate cubic yards?
Multiply length, width and depth in feet to get cubic feet, then divide by 27. With depth in inches: length × width × depth ÷ 324.
How many square feet does a cubic yard cover?
A cubic yard covers 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches and 81 sq ft at 4 inches.
How many cubic feet are in a cubic yard?
There are exactly 27 cubic feet in a cubic yard, because a yard is 3 feet and 3 × 3 × 3 = 27.
How much does a cubic yard weigh?
It depends on the material: roughly 1 ton for dry topsoil, 1.35 tons for dry sand, 1.4 tons for gravel and about 2 tons for wet concrete.
How many bags of mulch are in a cubic yard?
A cubic yard is 13.5 bags of 2 cu ft mulch, or 9 bags of 3 cu ft mulch.