How do I calculate cubic yards?

Multiply length by width in feet to get square feet, multiply by the depth in feet, and divide by 27. A 20 × 10 ft area at 4 inches (0.333 ft) is 66.7 cu ft, or 2.47 cubic yards.

How many cubic yards of gravel do I need for a 20×20 driveway?

At 4 inches deep, 400 sq ft × 0.333 ft = 133 cu ft, which is 4.9 cubic yards, about 6.9 tons of gravel. Order about 15 percent more for compaction.

How many bags of mulch are in a cubic yard?

A cubic yard is 27 cubic feet, so 13.5 bags of 2 cu ft mulch, or 9 bags of 3 cu ft. Bagged gravel and sand usually come in 0.5 cu ft bags: 54 per cubic yard.

How much does a cubic yard of topsoil weigh?

Around 1.2 tons when moderately moist, more when wet. Gravel is about 1.4 tons per cubic yard, sand 1.35, and mulch only about half a ton.

How do I convert square feet to cubic yards?

You need a depth. Square feet × depth in feet ÷ 27 = cubic yards. For a 3 inch layer, square feet × 0.25 ÷ 27, so 100 sq ft is 0.93 cubic yards.

Cubic Yards Calculator: Square Feet to Cubic Yards, Tons and Bags

A cubic yards calculator answers the question every landscaping order starts with: how much gravel, topsoil, sand or mulch covers this area to this depth?

Calculator

Cubic yards calculator: area × depth, with tons and bags

LengthWidthDepthGravel driveway 4–6 in, patio base 4 in, mulch 2–3 in, topsoil 2–4 in.Material (for weight and bag size)

Type length, width and depth. Square feet × depth in feet ÷ 27 = cubic yards.

Order 5–10 % extra for settling and uneven ground. For an irregular bed or driveway, draw its outline below and use that area.

A 16 × 12 ft outline. Click it to draw an irregular bed or driveway as a ground surface, curves included, and read its area.

About

Type the length, width and depth in feet and inches or metres and the result shows cubic yards, cubic feet and cubic metres, the weight in tons for the material you pick, and how many bags that is if you buy small. The formula is square feet × depth in feet ÷ 27, and this page does it for you with no rounding tricks; it is not an AI estimate. For a bed or driveway that is not a rectangle, draw its outline on the canvas below and use that area.

Square feet to cubic yards: the formula

Volume is area times depth. Measure the area in square feet, turn the depth into feet (3 inches is 0.25 ft), multiply, and divide by 27 because a cubic yard is 3 × 3 × 3 feet. A 10 × 12 ft bed at 3 inches deep is 120 sq ft × 0.25 ft = 30 cu ft, which is 1.11 cubic yards. In metric, area in square metres times depth in metres gives cubic metres, and a cubic metre is 1.31 cubic yards.

Suppliers sell by the cubic yard, sometimes by the ton, and bagged material by the cubic foot. The calculator shows all three so the number matches whichever price list you are reading.

Gravel driveway or path: 4 to 6 inches, compacted in layers.
Paver base: 4 inches of crushed stone under 1 inch of sand.
Mulch: 2 to 3 inches; topsoil for a new lawn: 2 to 4 inches.
Raised bed: the full depth of the box, usually 10 to 12 inches.

Cubic yards to tons

Weight depends on the material and how wet it is. The calculator uses typical delivered weights: gravel and pea gravel about 1.4 tons per cubic yard, crushed stone and road base 1.5, sand 1.35, topsoil 1.2, compost 1.0 and mulch about 0.5. These are US short tons. If the yard quotes by the ton, ask for their own density; wet sand or topsoil can weigh 10 to 20 percent more.

How much to order

Add 5 to 10 percent for uneven ground, settling and the pile you lose at the edges. Gravel and base material compact, so for a specified compacted depth order about 15 to 20 percent more loose. A pickup carries roughly one cubic yard of gravel or two of mulch; a dump truck delivers 10 to 15 yards.

Irregular areas

Curved beds, L-shaped patios and driveways with a turnaround are easier to draw than to split into rectangles. Draw the shape on the canvas with the Ground tool (gravel, mulch, garden bed or concrete), clicking each corner and dragging an edge’s midpoint where it curves, and the surface reports its area in square feet or square metres; then put that area into the calculator with the depth. The drawing is schematic, a planning sketch rather than a survey, and nothing here is an AI estimate.

Frequently asked questions

How do I calculate cubic yards?: Multiply length by width in feet to get square feet, multiply by the depth in feet, and divide by 27. A 20 × 10 ft area at 4 inches (0.333 ft) is 66.7 cu ft, or 2.47 cubic yards.
How many cubic yards of gravel do I need for a 20×20 driveway?: At 4 inches deep, 400 sq ft × 0.333 ft = 133 cu ft, which is 4.9 cubic yards, about 6.9 tons of gravel. Order about 15 percent more for compaction.
How many bags of mulch are in a cubic yard?: A cubic yard is 27 cubic feet, so 13.5 bags of 2 cu ft mulch, or 9 bags of 3 cu ft. Bagged gravel and sand usually come in 0.5 cu ft bags: 54 per cubic yard.
How much does a cubic yard of topsoil weigh?: Around 1.2 tons when moderately moist, more when wet. Gravel is about 1.4 tons per cubic yard, sand 1.35, and mulch only about half a ton.
How do I convert square feet to cubic yards?: You need a depth. Square feet × depth in feet ÷ 27 = cubic yards. For a 3 inch layer, square feet × 0.25 ÷ 27, so 100 sq ft is 0.93 cubic yards.

Sources

Where the numbers come from

Local amendments apply; check your own jurisdiction.

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