What a cubic yard is
A cubic yard is the volume of a cube one yard, three feet, on each side: 3 × 3 × 3 = 27 cubic feet. Because the foot is defined as exactly 0.3048 meters, a yard is exactly 0.9144 m and a cubic yard is 0.7646 cubic meters, 765 liters or 202.0 US gallons. The volume converter handles the rest of the units.
| One cubic yard equals | |
|---|---|
| Cubic feet | 27 |
| Cubic inches | 46,656 |
| Cubic meters | 0.7646 |
| Liters | 764.6 |
| US gallons | 202.0 |
| Bags of 2 cubic feet | 13.5 |
The formula
Dividing by 12 turns the depth from inches into feet, so the product is in cubic feet; dividing by 27 turns cubic feet into cubic yards. The two divisions can be combined into one: divide by 324. For a circular bed, the area is π times the radius squared, in feet, before multiplying by the depth. In metric the same job is length × width × depth in meters, which is already cubic meters.
How much a cubic yard covers
Coverage is 27 cubic feet divided by the depth in feet, which is 324 square feet divided by the depth in inches. The deeper the layer, the less area a yard covers, in exact proportion.
| Depth | Square feet per cubic yard | Square meters per cubic yard |
|---|---|---|
| 1 in | 324 | 30.1 |
| 2 in | 162 | 15.1 |
| 3 in | 108 | 10.0 |
| 4 in | 81 | 7.5 |
| 6 in | 54 | 5.0 |
| 8 in | 41 | 3.8 |
| 12 in | 27 | 2.5 |
Read the other way, a 100 square foot bed needs 100 ÷ 108 = 0.93 yards at 3 inches and 1.85 yards at 6 inches. The mulch calculator does this for any bed shape and depth and adds a settling allowance for soil.
Bags per cubic yard
Bagged material states its volume in cubic feet on the bag. Divide 27 by that number for the bags in a yard, and round up.
| Bag size | Bags per cubic yard | Bags to buy |
|---|---|---|
| 0.5 cu ft | 54.0 | 54 |
| 0.75 cu ft | 36.0 | 36 |
| 1 cu ft | 27.0 | 27 |
| 1.5 cu ft | 18.0 | 18 |
| 2 cu ft | 13.5 | 14 |
| 3 cu ft | 9.0 | 9 |
The table is where bulk delivery starts to look attractive: a yard of mulch is 14 bags of 2 cubic feet to carry, and a yard of soil 18 bags of 1.5. Concrete is sold by weight, not volume, and each bag's yield in cubic feet is printed on it; the concrete calculator turns a slab or post holes into bags using those yields.
Six projects worked out
Each row applies the formula to a common job. Depths are examples; use the depth your material and purpose call for.
| Project | Cubic feet | Cubic yards | Cubic meters | Bags of 2 cu ft |
|---|---|---|---|---|
| Flower bed 10 × 4 ft, 3 in of mulch | 10.0 | 0.37 | 0.28 | 5 |
| Raised bed 8 × 4 ft, 12 in of soil | 32.0 | 1.19 | 0.91 | 16 |
| Gravel path 30 × 3 ft, 4 in deep | 30.0 | 1.11 | 0.85 | 15 |
| Patio base 12 × 12 ft, 6 in deep | 72.0 | 2.67 | 2.04 | 36 |
| Concrete slab 10 × 10 ft, 4 in thick | 33.3 | 1.23 | 0.94 | 17 |
| Driveway 40 × 12 ft, 3 in of gravel | 120.0 | 4.44 | 3.40 | 60 |
Two of these rows are the usual cases for ordering bulk rather than bags. The 12 by 12 patio base at 6 inches is 2.67 yards, which is 36 bags of 2 cubic feet; the driveway is 4.44 yards. Gravel settles and compacts after it is spread, so suppliers and the gravel calculator add a compaction allowance on top of the geometric volume. Soil in a raised bed settles after watering too, which is why the mulch calculator's soil mode adds a percentage.
Volume is not weight
A cubic yard is a volume. What it weighs depends on the material and how wet it is, and that is the number that matters for a trailer, a pickup bed or a delivery truck's load limit. Suppliers quote tons per cubic yard for the specific stone, sand or soil they sell; use their figure, enter it into the gravel calculator's density field, and compare the result with what your vehicle is rated to carry rather than with a rule of thumb.
Ordering
- Measure in feet and inches, calculate in cubic feet, order in cubic yards. Suppliers sell by the yard and often in half-yard steps.
- Round up and add a margin for settling, compaction and uneven ground. Running short halfway through a pour or a path costs a second delivery.
- Compare bags with bulk once the job passes about half a yard: price per bag times bags per yard against the delivered price per yard.
- Check the weight with the supplier before collecting a yard yourself.
Frequently asked questions
How many cubic feet are in a cubic yard?
27. A yard is 3 feet, so a cube one yard on each side is 3 × 3 × 3 = 27 cubic feet. In metric a cubic yard is about 0.765 cubic meters, because a foot is exactly 0.3048 m and a yard therefore 0.9144 m.
How much does a cubic yard cover?
Divide 27 by the depth in feet, or 324 by the depth in inches. At 3 inches deep a cubic yard covers 108 square feet, at 2 inches 162, at 4 inches 81, at 6 inches 54. A 10 by 10 foot bed mulched 3 inches deep therefore needs just under a yard.
How many bags make a cubic yard?
Divide 27 by the bag size printed on the bag, in cubic feet: 13.5 bags of 2 cu ft, 18 bags of 1.5 cu ft, 27 bags of 1 cu ft, 36 bags of 0.75 cu ft. Round up, and compare the price of that many bags with the price of a bulk yard delivered.
How do I calculate cubic yards for a project?
Measure length and width in feet and depth in inches. Multiply length by width by depth, divide by 12 to turn the inch of depth into feet, and you have cubic feet; divide by 27 for cubic yards. A 12 by 12 foot patio base 6 inches deep is 12 × 12 × 6 ÷ 12 = 72 cubic feet, or 2.67 cubic yards. For a circle use π × radius² × depth.
How much does a cubic yard weigh?
It depends entirely on the material: a yard of dry mulch and a yard of wet gravel are very different loads. Suppliers quote weight per cubic yard for what they sell, and that figure, not a general one, is what decides whether a load fits a trailer or a pickup. The gravel calculator lets you enter the density your supplier gives you.