Cubic Yard Calculator

To calculate cubic yards, multiply length × width × depth (all in feet) to get cubic feet, then divide by 27. One cubic yard equals 27 cubic feet (3 ft × 3 ft × 3 ft). For example, a 10 ft × 10 ft area at 6 inches deep is 10 × 10 × 0.5 = 50 cubic feet, which is 50 ÷ 27 = 1.85 cubic yards.

The most common mistake is mixing units. Length and width are usually measured in feet, but depth is often in inches (like a 4-inch concrete slab or 3-inch mulch layer). Convert inches to feet first by dividing by 12 — a 4-inch slab is 0.333 feet, a 6-inch layer is 0.5 feet. Only after all three dimensions are in feet can you multiply them together.

For projects with multiple areas — a yard with three garden beds, or a driveway with a main section and a turn-out — calculate each area's volume separately and add the results. Add 5–10% waste. Full walkthrough: how to calculate cubic yards.

If you already know your area in square feet, the conversion to cubic yards is straightforward: multiply the square footage by the depth in feet, then divide by 27. For example, 200 square feet at 4 inches deep: 200 × (4 ÷ 12) = 66.67 cubic feet ÷ 27 = 2.47 cubic yards.

A useful shortcut skips the inch-to-feet conversion: cubic yards = square feet × depth (inches) ÷ 324. The 324 comes from 27 × 12 — it accounts for both the cubic-feet-to-yards and inches-to-feet conversions in one step. So 200 sq ft × 4 in ÷ 324 = 2.47 cubic yards, the same result.

The key thing to remember: you cannot convert square feet to cubic yards without a depth. Square feet measure area (2D); cubic yards measure volume (3D). Depth is the third dimension that connects them. Dedicated tools: square feet to cubic yards converter and square feet to cubic yards guide.

For a rectangular concrete slab, multiply length × width × thickness (all in feet), then divide by 27. A 10 × 10 foot slab at 4 inches thick is 10 × 10 × 0.333 = 33.3 cubic feet ÷ 27 = 1.23 cubic yards. Always add 5–10% for waste and uneven subgrades — for this slab, order 1.36 cubic yards.

For footings, columns, and round slabs, use the shape-specific formula. A round column 12 inches across and 8 feet tall: π × 0.5² × 8 = 6.28 cu ft ÷ 27 = 0.23 cu yd. Add all components together for the total order.

Once you have cubic yards, decide between ready-mix delivery and bagged concrete. Ready-mix is usually more cost-effective above about 1.5 cubic yards. For smaller jobs, use the bag table below — one cubic yard equals about 45 eighty-pound bags.

To convert cubic yards to tons, multiply by the material's density in tons per cubic yard. Volume and weight are different — a cubic yard of concrete weighs far more than a cubic yard of mulch. There is no universal conversion factor; you need the density for your specific material.

The densities below are typical loose, uncompacted values. Actual density varies with moisture content, gradation, compaction, and supplier. Full walkthrough: cubic yards to tons guide.

For round shapes — fire pits, round slabs, post holes, and tanks — use the cylinder formula: cubic yards = (π × radius² × height) ÷ 27, with radius and height in feet. Measure the radius as half the diameter (the full width across the circle).

To convert cubic yards back to square feet, you need the depth: square feet = (cubic yards × 27) ÷ depth in feet. This is useful when a supplier quotes a fixed number of cubic yards and you want to know how much area it will cover.

One cubic yard at 4 inches deep covers 81 square feet. At 6 inches deep, the same cubic yard covers only 54 square feet. Doubling the depth halves the coverage area for the same volume.