Cubic Feet Calculator

How this is calculated

Multiply length by width by height after converting every measurement to feet. The result in cubic feet is then converted to cubic yards by dividing by 27, and to metric units using exact conversion factors.

Formula

Frequently asked questions

How do I convert inches to feet first? Divide inches by 12. The calculator does this for you when you pick inches as the unit.

How many cubic feet are in a cubic yard? 27, because a yard is 3 feet and 3 × 3 × 3 = 27.

Worked example

A storage room is 10 ft long, 12 ft wide and 8 ft high. Volume = 10 × 12 × 8 = 960 ft³. That is 960 ÷ 27 ≈ 35.56 yd³, about 27.18 m³ or 27,184 liters, and roughly 7,181 US gallons.

Common mistakes

• Mixing units, such as feet for length and inches for height, in one calculation.
• Forgetting that a cubic yard is 27 cubic feet, not 3.
• Using outer dimensions for a container when you need the usable inner volume.

Tips

• Measure twice, and round up when ordering materials such as soil or gravel.
• For irregular spaces, split them into boxes, calculate each and add the volumes.

More questions

How do I find the cubic feet of a slab? Multiply length × width × depth, with the depth in feet. A 10 × 10 ft slab 4 in (0.333 ft) thick is 33.3 ft³.

Is a cubic foot a measure of weight? No. It is volume. Weight depends on the density of the material.

History and background

The foot has been used in many forms for thousands of years, with lengths that varied by region. The modern value was fixed in 1959, when the United States and other countries agreed that the international yard equals exactly 0.9144 meters, making the foot exactly 0.3048 meters and the cubic foot exactly 0.028316846592 cubic meters. Cubic feet remain common in the US for refrigerator capacity, shipping volume and airflow.

Putting it to use

Use this calculator to size a dumpster, estimate fill for a raised bed, check refrigerator or freezer capacity, or work out how much material a trench holds. For concrete or gravel, divide the cubic feet by 27 to order in cubic yards, then add 5 to 10% for waste.

Further questions

How many cubic feet are in a gallon? One US gallon is about 0.1337 cubic feet, so a cubic foot holds about 7.48 gallons.

How do I calculate the cubic feet of a cylinder? Use π × radius² × height with measurements in feet. The cylinder volume calculator does this directly.