Cubic Feet Calculator
Enter length, width and height in feet to get the volume in cubic feet, plus cubic yards and gallons.
To find cubic feet, multiply length by width by height, all measured in feet. The result is the volume in cubic feet. Divide by 27 to convert to cubic yards, or multiply by 7.48 to convert to US gallons. Cubic feet measures the space inside a three-dimensional shape.
How to Use This Calculator
Enter the length, width and height of the space or object in feet. If your measurements are in inches, divide each by 12 first to convert to feet. The calculator multiplies the three dimensions to give the volume in cubic feet.
Because cubic feet often needs converting for ordering materials or sizing containers, the result also shows the equivalent in cubic yards and in US gallons, so you can use whichever unit your project or supplier works in.
How the Calculation Works
Volume is the product of the three dimensions. When all three are in feet, the answer is in cubic feet — a cube one foot on each side.
The conversions follow fixed factors: one cubic yard is 27 cubic feet, so dividing by 27 gives cubic yards; and one cubic foot holds about 7.48 US gallons, so multiplying by 7.48 gives gallons. These are exact unit relationships, not estimates.
cubic feet = length × width × height (all in feet)
Worked Example
A box 3 feet long, 3 feet wide and 3 feet high has a volume of 3 × 3 × 3 = 27 cubic feet.
That converts to 27 ÷ 27 = 1 cubic yard, and 27 × 7.48 = 201.97 US gallons. The same three measurements give you all three units at once.
Assumptions and Limitations
- All three dimensions must be in feet; convert inches by dividing by 12
- Works for rectangular (box-shaped) volumes; other shapes need their own formula
- Gallon conversion uses US gallons (1 ft³ = 7.48052 gallons)
- Results are rounded for display
Who Uses a Cubic Feet Calculator
Shippers, movers, gardeners, and appliance shoppers use this to find a volume in cubic feet and convert it to yards or gallons. Enter length, width, and height to size a moving container, measure a refrigerator or freezer's capacity, work out soil for a raised bed, or estimate a tank's volume. It is the quick go-to whenever a space or container needs to be described by how much it holds.
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Open calculator →Frequently Asked Questions
How do I calculate cubic feet?
Multiply length by width by height, with all three measured in feet. A 3-by-3-by-3-foot space is 27 cubic feet. If your measurements are in inches, divide each by 12 first.
How many cubic feet are in a cubic yard?
Twenty-seven. A cubic yard is a cube three feet on each side, so 3 × 3 × 3 = 27 cubic feet. Divide cubic feet by 27 to get cubic yards.
How many gallons are in a cubic foot?
About 7.48 US gallons. Multiply a cubic-foot volume by 7.48 to convert it to US gallons, so 27 cubic feet is roughly 202 gallons.
How do I find cubic feet from inches?
Convert each measurement to feet by dividing by 12, then multiply the three. Alternatively, multiply the inches together and divide by 1,728, since there are 1,728 cubic inches in a cubic foot.
What is a cubic foot used for?
It measures volume — the space inside appliances, containers, shipping boxes, and quantities of soil, mulch or concrete. Many products such as freezers and refrigerators are rated in cubic feet.
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