Cubic Feet Calculator

A cubic foot is a unit of volume representing a space that measures 1 foot long, 1 foot wide, and 1 foot deep.

A cubic foot describes three-dimensional space, so calculating cubic feet requires three dimensions rather than just length and width.

For a rectangular space, multiply the length, width, and depth together. When all three dimensions are expressed in feet, the result is measured in cubic feet.

For example, a space measuring 10 feet long, 5 feet wide, and 2 feet deep has a volume of 100 cubic feet.

For a rectangular space, multiply the three dimensions together.

When measurements are provided in different units, convert them to compatible units before performing the calculation.

For example, if the length and width are measured in feet but the depth is given in inches, convert the depth to feet first by dividing the inch measurement by 12.

The calculator performs the applicable unit conversions automatically based on the supported units.

Measurements are often provided in inches, particularly for smaller construction, woodworking, and home-improvement projects.

If all three dimensions are measured in inches, multiply them to obtain cubic inches first. Then divide by 1,728 to convert the volume to cubic feet.

One cubic foot contains 1,728 cubic inches because 12 × 12 × 12 = 1,728.

If the calculator accepts inches as an input unit, enter the measurements directly and allow the calculator to perform the conversion.

Square feet measure area, while cubic feet measure volume. To convert a square-foot measurement into cubic feet, you also need the depth.

If the area is already known in square feet and the depth is measured in feet, multiply the square footage by the depth in feet.

If the depth is measured in inches, multiply the square footage by the depth in inches and divide by 12.

For example, an area of 500 square feet with a depth of 3 inches has a volume of 125 cubic feet.

Square footage alone cannot determine a volume without a depth or height.

Soil, topsoil, and other landscaping materials can be measured by volume.

For a rectangular soil area, multiply the length, width, and depth to calculate the geometric volume.

Measure the length and width of the area and determine the depth of soil to be added. Enter those dimensions into the calculator to determine the resulting volume.

Actual material requirements can vary because of settling, uneven surfaces, and other project conditions.

For a soil-specific calculation, use the Soil Calculator.

Concrete can also be measured in cubic feet.

For a rectangular concrete project, multiply the length, width, and thickness after converting the dimensions to compatible units.

For example, a project measuring 20 feet by 10 feet with a thickness of 4 inches first requires converting 4 inches to 0.333 feet. The resulting volume is approximately 66.67 cubic feet.

For calculations involving additional concrete-specific quantities supported by the Concrete Calculator, use the Concrete Calculator.

This calculator does not determine structural concrete thickness, reinforcement, building-code requirements, or engineering requirements.

Cubic feet and cubic yards are both units of volume.

One cubic yard contains 27 cubic feet. To convert a cubic-foot measurement to cubic yards, divide the cubic-foot volume by 27.

For example, 27 cubic feet equals 1 cubic yard, 54 cubic feet equals 2 cubic yards, and 81 cubic feet equals 3 cubic yards.

If you need to work specifically with cubic-yard measurements, use the Cubic Yard Calculator.

Cubic feet can be used to describe the volume of many construction and landscaping materials.

For a rectangular area, the calculation remains length × width × depth. The formula determines the volume of the space rather than the weight of the material.

Materials such as gravel, soil, and mulch can have different densities and may be sold using different measurement systems.

Do not convert cubic feet directly into pounds or tons without material-specific density information.

Accurate measurements are important because volume depends on all three dimensions.

For a rectangular area, measure the length from one end to the other, the width across the area, and the depth or height of the space.

Keep track of the units used for each measurement. If the measurements are in different units, the calculator can perform the applicable conversions supported by its interface.

For larger or irregular projects, divide the space into smaller rectangular sections when practical. Calculate each section separately and add the results together.

The cubic-foot calculation is particularly straightforward for rectangular spaces.

Common applications include storage areas, excavation and fill areas, rectangular garden beds, construction spaces, material volumes, rectangular containers, concrete forms, and gravel or landscaping areas.

For each rectangular section, calculate length × width × depth. If a project contains several rectangular sections, calculate each section separately and add the volumes together.

You can verify a rectangular calculation with a few simple steps.

First calculate the area by multiplying length × width. Then convert the depth if necessary by dividing inches by 12.

Multiply the square-foot area by the depth in feet to calculate cubic feet.

For example, 20 feet × 10 feet equals 200 square feet. At a depth of 6 inches, the depth is 0.5 feet. The resulting volume is 200 × 0.5 = 100 cubic feet.

If the manual result differs substantially from the calculator, check the dimensions, units, and depth entered.

Square feet and cubic feet describe different measurements.

Square feet measure area, while cubic feet measure volume.

For example, a 10-foot × 10-foot floor has an area of 100 square feet. If that same area has a 2-foot depth, its volume is 200 cubic feet.

A square-foot measurement alone cannot determine cubic feet without a depth or height.

Cubic feet are useful when the volume of a space or material needs to be expressed as a three-dimensional measurement.

Common applications include construction volume calculations, concrete volume, gravel volume, soil and topsoil volume, mulch volume, excavation and fill, rectangular containers and spaces, and conversions between cubic feet and cubic yards.

The appropriate volume unit depends on the size and type of project.

Use the dedicated material calculators when you need calculations specific to concrete, gravel, mulch, or soil.

If you need to calculate the area before determining volume, use the Square Footage Calculator.

For cubic-yard measurements, use the Cubic Yard Calculator.