Figure out how much mulch, soil, compost, stone or gravel you need before you order. Enter the length, width and depth of your project and the calculator gives you the amount to buy, rounded up to a whole unit so you do not run short. These are the same calculators you will find on our product pages, whether you are a homeowner planning a weekend project or a contractor pricing a job.
How the Calculators Work
Every calculator converts your measurements to feet, multiplies them, and rounds the answer up to the next whole unit. Here are the formulas.
- Mulch, soil, compost and gravel (cubic yards): length (ft) x width (ft) x depth (ft) / 27. If you enter depth in inches, divide it by 12 first to get feet.
- Large rock (cubic yards): length (ft) x width (ft) / 40.
- Small rock (cubic yards): length (ft) x width (ft) / 60.
- Square footage: length (ft) x width (ft).
One cubic yard is 27 cubic feet. For bagged products, divide 27 by the size of the bag: a 2 cu. ft. bag takes 13.5 bags to make a yard, so round up to whole bags.
Worked examples
- Mulch bed: a bed 20 ft long and 10 ft wide, mulched 3 inches deep. Depth is 3 / 12 = 0.25 ft. 20 x 10 x 0.25 = 50 cubic feet. 50 / 27 = 1.85, which rounds up to 2 cubic yards. In 2 cu. ft. bags, that is 50 / 2 = 25 bags.
- Topsoil for a garden: an area 15 ft by 12 ft, 4 inches deep. Depth is 4 / 12 = 1/3 ft. 15 x 12 x 1/3 = 60 cubic feet. 60 / 27 = 2.22, which rounds up to 3 cubic yards.
- Large rock path: a path 30 ft long and 4 ft wide. 30 x 4 = 120 sq. ft. 120 / 40 = 3 cubic yards.
- Small rock path: the same 30 ft by 4 ft path in small rock. 120 / 60 = 2 cubic yards.
- Square footage: a patio 18 ft long and 10 ft wide. 18 x 10 = 180 square feet.
Recommended Depth by Material
Use these typical depths as a starting point for the depth field. The last column shows how much ground one cubic yard covers at that depth (324 divided by the depth in inches). The rock calculators have the depth built in, so they only ask for length and width.
| Material | Typical depth | Sq. ft. covered by 1 cubic yard |
|---|---|---|
| Mulch | 2 to 3 inches | 108 to 162 |
| Topsoil for a new lawn | 4 to 6 inches | 54 to 81 |
| Garden or raised-bed soil | 6 to 12 inches | 27 to 54 |
| Compost, top-dressing a lawn | 1/4 to 1/2 inch | 648 to 1,296 |
| Compost, mixed into soil | 2 to 3 inches | 108 to 162 |
| Decorative gravel | 2 to 3 inches | 108 to 162 |
| Small rock (small rock calculator) | Built into the calculator | About 60 |
| Large rock (large rock calculator) | Built into the calculator | About 40 |
Frequently Asked Questions
How many bags are in a cubic yard?
A cubic yard is 27 cubic feet. That is 13.5 bags of 2 cu. ft. mulch or soil, or 9 bags of 3 cu. ft. To check any other size, divide 27 by the cubic feet printed on the bag. Bags are sold whole, so round up.
How much area does one cubic yard cover?
One cubic yard covers about 162 square feet at 2 inches deep, 108 square feet at 3 inches deep, 81 square feet at 4 inches deep and 54 square feet at 6 inches deep. Divide 324 by the depth in inches to get the square feet for any depth.
How deep should I spread mulch?
Most beds do well with 2 to 3 inches of mulch. A thinner layer lets weeds come through, and a much thicker layer can hold too much moisture against plants. Keep mulch pulled back from stems and trunks.
Will a cubic yard fit in my truck?
It depends on your truck. A cubic yard of loose material is 27 cubic feet and can weigh a lot, especially stone and wet soil. Check your truck's rated payload and bed size before you load, and contact us to ask about your options if a full yard is too much.
What if my result falls between sizes?
The calculators round up to the next whole unit so you do not run short. A result of 3 cubic yards may really be 2.1 yards. Settling and uneven ground also use extra material, so rounding up is usually the safer choice. Contact us if you want help deciding.
How do I measure a sloped or irregular area?
Break the area into simple rectangles, calculate each one, and add the results together. For a circle or curved bed, measure the widest length and width and treat it as a rectangle, which leaves a small cushion. On a slope, measure along the ground rather than straight across.
What units do I enter my measurements in?
Length and width are entered in feet. If you measured in inches, divide by 12 first, so 6 inches is 0.5 feet. The mulch, soil and compost calculator lets you enter depth in either inches or feet.
What is the difference between the large rock and small rock calculators?
They use different coverage rates. The large rock calculator assumes one cubic yard covers about 40 square feet, and the small rock calculator assumes about 60 square feet. Use the one that matches the size of the stone you are buying.
Ready to Order?
Once you know how much you need, shop our materials.