Cubic Feet Calculator
Enter the length, width and height in any unit to get the volume in cubic feet, plus cubic yards, cubic meters, liters and US gallons.
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Leave at 1 for a single space.
- Cubic yards
- 4.4444
- Cubic inches
- 207,360
- Cubic meters
- 3.398
- Liters
- 3,398.02
- US gallons
- 897.66
How this was calculated
- Convert to feet: 10 ft = 10 ft, 4 ft = 4 ft, 3 ft = 3 ft
- Volume = 10 × 4 × 3 = 120 ft³
How this cubic feet calculator works
Cubic feet measure the space inside a box, room, freezer, trailer or planter. This cubic feet calculator converts the length, width and height to feet, multiplies the three numbers, and shows the answer in cubic feet, cubic yards, cubic inches, cubic meters, liters and US gallons. Each side has its own unit, so a box measured as 24 in × 18 in × 2 ft works without converting anything by hand.
The formula, with a worked example
Volume = length × width × height, all in feet. A planter that is 10 ft long, 4 ft wide and 3 ft deep holds 10 × 4 × 3 = 120 cubic feet. For smaller items convert inches to feet first by dividing by 12: a moving box that is 18 in × 18 in × 16 in is 1.5 ft × 1.5 ft × 1.333 ft = 3.0 cubic feet. Doing the math in inches gives the same result (5,184 cubic inches) once you divide by 1,728, the number of cubic inches in one cubic foot.
Cubic feet to other units
- 1 cubic yard = 27 cubic feet (3 × 3 × 3).
- 1 cubic foot = 1,728 cubic inches (12 × 12 × 12).
- 1 cubic foot = 28.3168 liters, or about 7.48 US gallons.
- 1 cubic meter = 35.3147 cubic feet.
Volume units scale with the cube of the length unit, which is why 1 yard is 3 feet but 1 cubic yard is 27 cubic feet and not 3.
Common mistakes
The most frequent error is mixing units, such as multiplying 10 feet by 4 feet by 36 inches and calling the result cubic feet. Convert 36 inches to 3 feet first. The second is treating the outside size as the usable space: a refrigerator or cooler listed at 18 cubic feet is measured inside, and wall thickness removes a lot of volume. The third is rounding too early; keep a few decimals until the final answer.
When cubic feet matter
Cubic feet are the standard unit for refrigerator and freezer capacity, storage units, shipping and moving volume, air conditioning airflow (cubic feet per minute) and bagged soil or mulch. For bulk landscaping material use the cubic yard calculator, which adds a waste allowance, and for cylinders, cones and spheres use the volume calculator.
Frequently asked questions
How do you calculate cubic feet?
Multiply length × width × height, all in feet. A box 10 ft long, 4 ft wide and 3 ft high is 10 × 4 × 3 = 120 cubic feet. If a side is in inches, divide it by 12 first.
How do you calculate cubic feet from inches?
Multiply the three measurements in inches and divide by 1,728 (12 × 12 × 12). A box that is 18 in × 18 in × 16 in is 5,184 cubic inches, which is 3 cubic feet.
How many cubic feet are in a cubic yard?
27 cubic feet, because a yard is 3 feet and 3 × 3 × 3 = 27. To convert cubic feet to cubic yards, divide by 27.
How many gallons are in a cubic foot?
One cubic foot is 28.3168 liters, which is about 7.48 US gallons.
How many cubic feet are in a cubic meter?
One cubic meter is 35.3147 cubic feet, because 1 m = 3.28084 ft and 3.28084 cubed is 35.3147.