How Many Cubic Feet Are in a Cubic Yard? 27, Plus Quick Conversions

There are 27 cubic feet in 1 cubic yard. A yard is 3 feet long, and 3 ft × 3 ft × 3 ft = 27 cubic feet.

To go from cubic feet to cubic yards, divide by 27. To go the other way, multiply by 27. One cubic foot is 1 ÷ 27 = 0.0370 cubic yard.

Why is a cubic yard 27 cubic feet and not 3?

If you are asking how many cubic feet in a cubic yard, the answer is 27 because a cubic yard measures volume, so the 3 ft that make a yard show up three times: length, width and height.

• 1 yard = 3 feet
• 1 square yard = 3 × 3 = 9 square feet
• 1 cubic yard = 3 × 3 × 3 = 27 cubic feet

The same cube is 36 in on each edge, so it holds 36 × 36 × 36 = 46,656 cubic inches (27 × 1,728). NIST Handbook 44 lists the cubic yard as exactly 27 cubic feet. In metric it is 0.764554857984 cubic meters, and in liquid terms about 201.97 US gallons. When a supplier says “a yard of gravel” or “a yard of mulch,” they mean a cubic yard. Gravel and sand are often sold by weight too, so see how many cubic yards are in a ton.

How do you convert cubic feet to cubic yards, and back?

cubic yards = cubic feet ÷ 27
cubic feet = cubic yards × 27

How do you get cubic yards from length, width and depth?

Most jobs start with length, width and a depth in inches, not with cubic feet. Convert the depth to feet first (divide inches by 12), multiply to get cubic feet, then divide by 27. Circles, triangles and square-feet shortcuts are in how to calculate cubic yards.

cubic yards = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27

Example 1: a concrete slab. The slab is 10 ft × 10 ft and 4 in thick.

• Depth: 4 ÷ 12 = 0.3333 ft
• Volume: 10 × 10 × 0.3333 = 33.333 cubic feet
• Cubic yards: 33.333 ÷ 27 = 1.2346

Example 2: a mulch bed. The bed is 20 ft × 15 ft and 3 in deep.

• Depth: 3 ÷ 12 = 0.25 ft
• Volume: 20 × 15 × 0.25 = 75 cubic feet
• Cubic yards: 75 ÷ 27 = 2.7778

Because 27 × 12 = 324, there is a shortcut: square feet × depth in inches ÷ 324 = cubic yards. For the slab, 100 × 4 ÷ 324 = 1.2346. The same factor tells you how far one cubic yard goes: it covers 324 sq ft at 1 in deep, which UF/IFAS also gives for mulch.

Bag sizes to cubic yards

Divide 27 by the volume of one bag. Bag volumes are on the label, and they differ by product.

* Yields printed on the QUIKRETE Concrete Mix 1101 and SAKRETE High Strength data sheets. Other products and specialty mixes can differ, so use the number on your bag. Step-by-step ordering is in how many bags of concrete you need and how many bags of mulch are in a yard. Concrete bags are also sold by the pallet: see how many bags of concrete are on a pallet.

Common mistakes

• Dividing by 3 or 9. Those are for linear yards and square yards. Volume needs 27.
• Skipping the inches-to-feet step. A 4 in slab uses 4 ÷ 12 ft, not 4.
• Rounding down. Round purchases up, and add an allowance for uneven ground, settling and spillage. These are not in the arithmetic.
• Mixing the labels. Feet, yards, square and cubic units cannot be added or compared directly. Convert everything to cubic feet first.

Questions people ask