Bulk material usually arrives loose and is priced per cubic yard, and one cubic yard is 27 cubic feet, or about 0.765 cubic meters. Bagged products list their volume in cubic feet, and some are sold by weight, so tons and bag counts come from the material calculators.
How to use this calculator
- Pick the shape: a rectangle for beds, strips and driveway toppings, a circle for a round tree ring, or a triangle for a corner bed with a right-angle corner.
- Enter the length and width, or the diameter, in the unit you measured in. For a triangle, the length is the base and the width is the height.
- Enter the depth of the finished layer, and check the unit selector beside it, since inches and feet give very different totals.
- Read the cubic yards figure to order by the yard, or the cubic feet and cubic meters figures to match a supplier's unit.
- For identical pieces, such as several tree rings of one size, enter the count in the quantity field.
- Enter the price per cubic yard to see an estimated material cost. The figure excludes delivery.
Worked examples
Front flower bed
20 ft × 4 ft, 3 in deep
- cubic yards
- 0.741
- cubic feet
- 20
Round tree ring
10 ft diameter, 3 in deep
- cubic yards
- 0.727
- cubic feet
- 19.63
Driveway topping
40 ft × 10 ft, 2 in deep
- cubic yards
- 2.47
- cubic feet
- 66.67
Triangular corner bed
triangle 12 ft base × 8 ft height, 3 in deep
- cubic yards
- 0.444
- cubic feet
- 12
Cubic yards for common bed and yard sizes at several depths
| Area | 2 in deep | 3 in deep | 4 in deep | 6 in deep |
|---|---|---|---|---|
| 8 × 10 ft | 0.494 | 0.741 | 0.988 | 1.48 |
| 10 × 10 ft | 0.617 | 0.926 | 1.23 | 1.85 |
| 12 × 12 ft | 0.889 | 1.33 | 1.78 | 2.67 |
| 10 × 20 ft | 1.23 | 1.85 | 2.47 | 3.7 |
| 20 × 20 ft | 2.47 | 3.7 | 4.94 | 7.41 |
Cubic yards, exact volume without extra for waste.
Why bulk material is sold by the cubic yard
Loose material is easy to measure as a volume but awkward to weigh on site, so suppliers load and price it by the yard. A cubic yard is a cube one yard on each side, and it holds 27 cubic feet. For a small pour mixed from bags, the concrete calculator counts the bags.
Convert the length and width to feet, convert the depth to feet by dividing the inches by 12, multiply the three figures to get cubic feet, and then divide by the cubic feet in a cubic yard. The calculator runs these steps for you, but knowing them helps when a supplier quotes in another unit.
Measuring an irregular area
Break an irregular bed into simple shapes, find the area of each one, and add them together before you multiply by depth. The calculator runs one shape at a time, so enter each piece separately and add the cubic yards yourself.
- Rectangle: length times width. This covers most beds and strips.
- Circle: pi times the radius squared. The radius is half the diameter, so measure straight across the middle.
- Triangle: half of base times height. For a right-angle corner, the two straight edges are the base and the height.
- Curved edges: measure the width at a few points and use the average.
How depth changes the total
Depth scales the total in step with the plan area, so a deeper layer needs proportionally more material, and the same load covers less ground.
Extension guidance for most beds puts mulch at 2 to 3 inches. At 3 inches, one cubic yard covers 108 square feet. Measure the depth where the material will sit after it is raked, not the depth you hope for.
Ordering a little extra
Order a little more than the exact figure. Ground is rarely level, edges are hard to cut square, and packed soil needs more loose material than the finished layer. A small margin is easier to plan for than a second delivery halfway through the job.
Choose the margin for your own ground and material. For a per-ton quote, the gravel calculator turns the same volume into tons, and for bagged mulch, the mulch calculator counts the bags for you.
How do I find the cubic yards for a trapezoid-shaped bed?
Add the two parallel sides, divide by two, and multiply by the distance between them. That gives the area. Or split the bed into a rectangle and a triangle and enter each one in the calculator. Then multiply by the depth as usual.
Common questions
How much area does one cubic yard cover?
Area depends on depth. Spread 12 inches deep, one cubic yard covers 27 square feet, and spread 2 inches deep it covers 162 square feet.
Why divide by the cubic feet in a cubic yard?
The length, width and depth are in feet, so their product is cubic feet. A cubic yard holds 27 cubic feet, so dividing by that count converts the total into cubic yards.
How do I convert cubic feet to tons?
This calculator stops at cubic yards, because weight depends on the material. Multiply the cubic yards by the weight per cubic yard that your supplier gives for that product. Loose gravel, for example, weighs 1.4 tons per cubic yard.
Does the cost include delivery?
No. The estimate multiplies the cubic yards by the price you enter, so it covers the material only. Delivery, a minimum load or a short-load fee comes on top, so ask for the full quote before you compare suppliers.
How much extra dirt should I order for fill that will be compacted?
For fill that will be packed down, a common starting point is to add 15 percent to the exact volume. Soil shrinks by different amounts when compacted: clay about 10 to 18 percent, sand about 11 to 35 percent, and rocky soil about 5 to 22 percent. Adjust the extra for the soil you have.
How do I convert square feet to cubic yards?
Multiply the area in square feet by the depth in feet. To get feet, divide the depth in inches by 12 inches. Then divide the result by 27 cubic feet to get cubic yards. If you only have cubic inches, divide by 1,728 cubic inches first to get cubic feet.
How many bags of mulch or soil make a cubic yard?
Divide the cubic feet in a yard, 27 cubic feet, by the size printed on the bag. Mulch bags are commonly 2 cu ft or 1.5 cu ft, and garden soil bags are commonly 1.5 cu ft. Round up to a whole bag.
How many tons is a cubic yard of decomposed granite (DG)?
Decomposed granite weighs about 1.5 tons per cubic yard. The exact figure shifts with moisture and the fines content, so check your supplier's number before you order by weight.