The same unit is used for length, width and height.
How to use this calculator
Enter the length, width and height (or depth) in the same unit, choose the unit and press Calculate. The result is shown in cubic yards, cubic feet, cubic meters and US gallons. Use it for soil, mulch, gravel, sand or concrete.
The formula
Cubic feet = length × width × height (all in feet)
Cubic yards = cubic feet ÷ 27
Example: An area 10 ft × 10 ft and 1 ft deep is 100 cubic feet, which is 3.70 cubic yards or 2.83 cubic meters.
How to use your cubic yard estimate when ordering material
Bulk soil, gravel, mulch, sand and ready-mix concrete are usually sold by the cubic yard. Your result tells you how much space the material needs to fill. Use it as the starting point for your order, then adjust for the material and the site.
Measure depth correctly
Depth is where most mistakes happen. A small change makes a big difference because depth multiplies the whole area.
- Measure depth in several spots and use the average.
- Enter inches as inches, or divide by 12 first if you work in feet. A 4-inch layer is 0.33 ft, not 0.4 ft.
- For a sloped area, measure the shallow and deep ends and average them.
- Use the quantity field when you have several identical beds or pads.
A worked example
A 12 ft by 10 ft patio base with 4 inches of gravel works out to 12 × 10 × 0.333 = 40 cubic feet. Divided by 27, that is about 1.48 cubic yards. Most suppliers sell in quarter or half yards, so you would order 1.5 to 1.75 yards to leave a small margin.
Add extra for compaction and waste
Loose material settles and compacts once it is spread and tamped. A few rules of thumb:
- Gravel and road base: add about 10 to 15 percent if you will compact it.
- Topsoil and fill dirt: add about 10 to 20 percent for settling.
- Mulch: add about 5 to 10 percent.
- Concrete: add about 5 to 10 percent for uneven ground and spills.
Think about weight and delivery
Volume is not the whole story. Topsoil and gravel are heavy, typically more than a ton per cubic yard, depending on moisture and type. A standard pickup can usually carry only a fraction of a yard of these materials safely. Check your truck’s payload rating, or pay for delivery.
When you get quotes, ask whether the price includes delivery, whether there is a minimum order, and where the truck can dump the load. Place a tarp down if it must go on the driveway. Plan a path for wheelbarrows before the load arrives.
Common mistakes
- Forgetting to convert inches to feet.
- Ordering the exact number with no margin, then paying a second delivery fee.
- Assuming a cubic yard of every material weighs the same.
For structural concrete such as footings, slabs that carry vehicles or retaining walls, check local building codes and consider a licensed contractor.
