Cubic Feet Calculator
Created by: Ethan Brooks
Last updated:
To calculate cubic feet, multiply length × width × height in feet. A 10 × 8 × 9 ft room is 720 cubic feet. If you measured in inches, multiply the three numbers and divide by 1,728: an 18 × 18 × 16 inch box is 3 cubic feet. The calculator below accepts inches, feet, yards or meters and also handles cylinders.
Cubic Feet Calculator
MathMultiply length × width × height in feet, or enter inches and the calculator divides by 1,728 for you.
Cubic feet of common boxes and spaces
| Item | Dimensions | Cubic feet |
|---|---|---|
| Shoebox | 13 × 8 × 5 in | 0.30 |
| Small moving box | 16 × 12 × 12 in | 1.33 |
| Medium moving box | 18 × 18 × 16 in | 3.00 |
| Large moving box | 18 × 18 × 24 in | 4.50 |
| Extra-large moving box | 24 × 18 × 24 in | 6.00 |
| Wardrobe box | 24 × 21 × 46 in | 13.42 |
| Standard pallet load, 4 ft high | 48 × 40 × 48 in | 53.33 |
| 10 × 10 ft room, 8 ft ceiling | 10 × 10 × 8 ft | 800 |
| 12 × 12 ft room, 8 ft ceiling | 12 × 12 × 8 ft | 1,152 |
| 10 × 10 ft storage unit, 8 ft high | 10 × 10 × 8 ft | 800 |
| 4 × 8 ft raised bed, 1 ft deep | 8 × 4 × 1 ft | 32.00 |
| 20 ft shipping container (inside) | 19.33 × 7.67 × 7.83 ft | 1,161 |
| 26 ft moving truck box (approx.) | 26 × 8 × 8 ft | 1,664 |
Moving box sizes vary by brand. Container and truck figures are approximate inside dimensions.
Cubic feet formulas
- Box or room: length × width × height (in feet).
- Dimensions in inches: length × width × height ÷ 1,728.
- Cylinder: 3.14159 × (diameter ÷ 2)² × height.
- Sphere: 4/3 × 3.14159 × radius³.
Convert every measurement to the same unit before multiplying. Mixing feet and inches is the most common mistake: 10 ft × 8 ft × 6 in is 10 × 8 × 0.5 = 40 cubic feet, not 480.
Converting cubic feet
- Cubic yards = cubic feet ÷ 27
- U.S. gallons = cubic feet × 7.48
- Liters = cubic feet × 28.32
- Cubic meters = cubic feet ÷ 35.31
Worked examples
- Garden bed, 8 × 4 ft, 10 inches deep: 8 × 4 × (10 ÷ 12) = 26.7 cubic feet, or about 1 cubic yard of soil.
- Shipping box, 24 × 18 × 18 inches: 7,776 ÷ 1,728 = 4.5 cubic feet.
- Room, 12 × 14 ft with a 9 ft ceiling: 12 × 14 × 9 = 1,512 cubic feet of air.
Frequently Asked Questions
How do I calculate cubic feet?
Multiply length × width × height, with all three in feet. A space 10 ft long, 8 ft wide and 9 ft high is 10 × 8 × 9 = 720 cubic feet.
How do I calculate cubic feet from inches?
Multiply the three dimensions in inches and divide by 1,728, the number of cubic inches in a cubic foot. An 18 × 18 × 16 inch box is 5,184 cubic inches, which is 5,184 ÷ 1,728 = 3.0 cubic feet.
How do I calculate the cubic feet of a cylinder?
Use π × radius² × height, with the radius being half the diameter. A round tank 3 ft across and 4 ft high is 3.14159 × 1.5² × 4 = 28.3 cubic feet.
How many gallons are in a cubic foot?
One cubic foot holds 7.48 U.S. gallons (28.32 liters). A U.S. gallon is defined as 231 cubic inches, and a cubic foot is 1,728 cubic inches.
How do I convert cubic feet to cubic yards?
Divide cubic feet by 27, because a cubic yard is 3 × 3 × 3 feet. Soil, mulch, gravel and concrete are usually sold by the cubic yard: 54 cubic feet is 2 cubic yards.
What does 10 cubic feet look like?
About the size of a chest freezer or a small refrigerator’s fresh-food section, or roughly three medium moving boxes. A cube 2.15 feet (26 inches) on each side holds 10 cubic feet.
Sources and References
- NIST: Unit conversion. Volume factors, including 1 cubic foot = 28.316 846 liters.
- NIST Special Publication 811. Appendix B: the U.S. liquid gallon is 231 cubic inches.