Cubic Feet Calculator
Enter length, width, and height below to instantly get volume in cubic feet.
How to Calculate Cubic Feet
Cubic feet = length × width × height.
A common mistake is multiplying dimensions that are still in different units — say, a length already converted to feet but a width left in inches. Convert every dimension to feet first (divide inches by 12) before multiplying; otherwise the result won't represent real cubic feet, since volume in cubic units compounds any unit mismatch three times over.
Worked example
A box 4 ft long, 3 ft wide, and 2 ft tall.
4 × 3 × 2 = 24
Volume: 24 ft³
A second example, a bed 6 ft long, 5 ft wide, and 3 ft deep.
6 × 5 × 3 = 90
Volume: 90 ft³, or 90 / 27 ≈ 3.33 cubic yards.
Keep going
- Cubic feet adds a height on top of a flat area calculation; the square footage calculator isolates just that area before height is factored in. Square Footage Calculator
Frequently Asked Questions
How do you calculate cubic feet?
Multiply length × width × height, all measured in feet: cubic feet = L × W × H.
How do you convert inches to cubic feet?
Convert each dimension to feet first (divide by 12), then multiply the three feet measurements together — or multiply in inches and divide the final cubic-inch result by 1,728 (12³).
What is cubic feet used for?
It measures volume — how much space something takes up or holds, commonly used for shipping boxes, storage units, soil/mulch quantities, and appliance capacities like refrigerators.
How many cubic feet are in a cubic yard?
27. A yard is 3 feet, so a cubic yard is 3 ft × 3 ft × 3 ft = 27 cubic feet. This conversion matters because concrete, mulch, and topsoil are usually sold by the cubic yard — divide your cubic feet total by 27 to get the cubic yards to order.
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