Cubic Yards Calculator

Cubic yards at a glance#

A cubic yards calculator works out the volume of a space in cubic yards from its length, width and depth. Measure all three in feet, multiply them together to get cubic feet, then divide by 27, because 1 cubic yard equals 27 cubic feet. In short: cubic yards = (length in feet x width in feet x depth in feet) / 27.

Worked example: a 10 ft by 10 ft area covered 3 inches deep. First convert the depth to feet, since 3 inches is 0.25 ft. Then 10 x 10 x 0.25 = 25 cubic feet, and 25 / 27 = 0.93 cubic yards.

Depth is usually given in inches, so convert it to feet first by dividing by 12. Common depths:

Enter your length, width and depth in the calculator above for the exact result in cubic yards, cubic feet and cubic meters. It handles the inch-to-foot conversion and other shapes (circle, triangle, trapezoid) for you. Order a little extra, around 5 to 10%, to allow for settling and uneven ground when buying gravel, mulch or concrete.

How to use the cubic yards calculator#

Choose the shape of your area (rectangle, circle, triangle or trapezoid), enter its dimensions and the depth, then read the volume in cubic yards, cubic feet and cubic meters. If you measure depth in inches, the calculator converts it for you. The core rule is the same for every shape: find the area, multiply by depth to get cubic feet, then divide by 27 to get cubic yards.

Volume by shape#

The depth stays the same for every shape; only the area formula changes.

• Rectangle: area = length x width.
• Circle: area = pi x radius² (radius is half the diameter).
• Triangle: area = (base x height) / 2.
• Trapezoid: area = ((side a + side b) / 2) x height.

In each case, volume in cubic feet = area in square feet x depth in feet, and cubic yards = cubic feet / 27.

Example: concrete for a circular patio#

A circular patio 10 ft across, poured 6 inches deep. Convert depth to feet: 6 inches = 0.5 ft. The radius is 5 ft, so the area is pi x 5², about 78.54 square feet. Volume is 78.54 x 0.5 = 39.27 cubic feet, and 39.27 / 27 = 1.45 cubic yards.

Example: gravel for a driveway#

A driveway 20 ft by 10 ft, covered 4 inches deep. Depth in feet is 4 / 12 = 0.33 ft. Area is 20 x 10 = 200 square feet. Volume is 200 x 0.333 = 66.7 cubic feet, and 66.7 / 27 = 2.47 cubic yards. Order about 5 to 10% extra to allow for settling.

Frequently asked questions#

How do you calculate cubic yards for a rectangular area?#

Measure length, width and depth in feet. Multiply length by width for the area, multiply by depth for cubic feet, then divide by 27. A 12 ft by 9 ft area, 6 inches (0.5 ft) deep, is 12 x 9 x 0.5 = 54 cubic feet, or 2 cubic yards.

How much mulch do I need for a garden bed?#

Multiply the bed length by its width to get square feet, then by the mulch depth in feet. A 10 ft by 5 ft bed at 3 inches (0.25 ft) is 50 x 0.25 = 12.5 cubic feet, which is 12.5 / 27 = 0.46 cubic yards.

How do you convert square feet to cubic yards?#

Square feet is an area, so you need a depth to get volume. Multiply the square footage by the depth in feet for cubic feet, then divide by 27. There is no fixed square-feet-to-cubic-yards factor without a depth.

Why divide by 27?#

One cubic yard is 3 ft by 3 ft by 3 ft, which is 27 cubic feet. Dividing cubic feet by 27 converts the volume into cubic yards.

How much extra should I order?#

Add roughly 5 to 10% over the calculated volume. That covers settling, compaction and uneven ground so you do not run short mid-project.