Cubic Yard Calculator: How Many Yards Do You Need?
Concrete for a slab, mulch for the beds, gravel for the drive and soil for a new lawn have one thing in common: they are all sold by the cubic yard, a unit most of us rarely picture until the delivery truck is booked. Order too little and the job stops while you pay for a second delivery; order too much and you pay to haul the surplus away. This cubic yard calculator turns a length, a width and a depth into the volume you actually need, in cubic yards, cubic feet and cubic metres, for rectangular and circular areas, with a waste allowance added before you order.
What is a cubic yard?
A cubic yard is a cube that measures 3 feet on every side — 3 ft long, 3 ft wide and 3 ft deep. Multiply it out and one cubic yard holds 27 cubic feet. That single number, 27, sits underneath every conversion on this page: work out a volume in cubic feet, divide by 27, and you have cubic yards. If it helps to picture it, a cubic yard of mulch is roughly the load in the back of a standard pickup truck, filled level with the sides of the bed.
Coverage is where the unit becomes practical. Spread one cubic yard 1 inch deep and it covers 324 square feet — a generous patio or a long garden path. At 3 inches deep, the depth most mulch beds want, the same yard covers 108 square feet. At 4 inches, the standard depth for a concrete slab, it covers 81 square feet. Depth eats coverage fast, which is why a small error with the tape or the depth gauge makes such a big difference to the size of the order.
Cubic Yard Calculator
Choose a shape, enter your dimensions, and the results update as you type — or press Calculate. Several identical areas and a waste allowance are handled in the same step.
Enter your measurements, then press Calculate.
Formulas: rectangle = length × width × depth; circle = π × radius² × depth, with radius = diameter ÷ 2. Cubic yards = cubic feet ÷ 27; cubic metres = cubic feet ÷ 35.31.
How to work it out
The hand method follows the same steps as the calculator. First find the area: length multiplied by width for a rectangle, or π × radius² for a circle, where the radius is half the diameter. Then multiply the area in square feet by the depth — converted from inches into feet — to get cubic feet. Divide by 27 to turn cubic feet into cubic yards, multiply by the number of identical areas, and finally add your waste percentage. For a circle, the calculator asks for the diameter and halves it for you.
Depths are usually quoted in inches, so convert them before you multiply. The conversions you will use most often are:
| Depth (inches) | Depth (feet) |
|---|---|
| 2 in | 0.167 ft |
| 3 in | 0.25 ft |
| 4 in | 0.333 ft |
| 6 in | 0.5 ft |
| 12 in | 1 ft |
Check it against a job you can verify: a 10 × 10 ft patio base, 4 inches deep. The area is 100 square feet and 4 inches is 0.333 ft, so the volume is 100 × 0.333 = 33.33 cubic feet. Divide by 27 and you get 1.23 cubic yards net. Add the standard 10% waste allowance and the order figure is 1.36 cubic yards. A perfect cube check works too: 3 × 3 ft at 36 inches deep is exactly 27 cubic feet — precisely one cubic yard.
Typical depths
Every material has a depth it performs at, and going thinner to save money usually costs more later — a slab that cracks or a mulch layer that lets weeds through within a month. These are the depths most suppliers and installers work to:
| Material / job | Typical depth |
|---|---|
| Mulch beds | 2–3 in |
| Concrete slab | 4 in |
| Gravel base | 4–6 in |
| Topsoil for lawns | 4–6 in |
| Sand bed for pavers | 1 in |
Loose materials also settle and compact after delivery. Gravel packs down under its own weight and traffic, soil shrinks as it beds in, and mulch compresses as it starts to break down. That is the practical reason the waste field on this calculator starts at 10%: it covers uneven ground, spillage on the way from the pile to the barrow, and the settling of the first few weeks, so the finished depth is the depth you planned.
What to calculate next
A cubic yard is a volume, not a shopping list. Once you know how many yards a job needs, the material calculators turn that volume into bags, tons and costs for the specific material you are buying:
- Concrete Calculator — yards, bags and ready-mix cost for slabs, footings and post holes.
- Mulch Calculator — bags or bulk yards for garden beds, with a depth guide.
- Gravel Calculator — tons and cubic yards for driveways, paths and bases.
- Square Footage Calculator — the area of any shape, before you add a depth.
Frequently asked questions
How many cubic feet are in a cubic yard?
27. A cubic yard is a cube 3 ft × 3 ft × 3 ft, and 3 × 3 × 3 = 27. To convert any volume from cubic feet to cubic yards, divide by 27; to go the other way, multiply by 27.
How much area does a cubic yard cover?
It depends on the depth. One cubic yard covers 324 square feet at 1 inch deep, 108 square feet at 3 inches, and 81 square feet at 4 inches. Double the depth and you halve the coverage, so measure the depth as carefully as the length and width.
Do I need extra for waste and settling?
Yes. Add 10% as standard — it covers uneven ground, spillage, and the way loose materials settle and compact after they are spread. This calculator adds the waste percentage you enter to the net volume and shows you both figures, so you can see the neat measurement and the order quantity side by side.
Is a cubic yard the same as a ton?
No. A cubic yard measures volume and a ton measures weight, and the same yard weighs very differently from one material to the next. A cubic yard of gravel weighs roughly 1.4 tons, while a yard of dry soil weighs less. If you are buying by weight, the material calculators on this site — gravel, mulch, topsoil and concrete — convert volume into tons or bags for you.
Estimates only — measure twice before ordering materials.