Cubic Feet Calculator
Convert cubic feet between units instantly. Includes conversion tables, common equivalents, and calculation formulas. Free to use with no signup required.
Formula
Cubic Feet = Length (ft) x Width (ft) x Height (ft)
Multiply three dimensions in feet to get cubic feet. When dimensions are in other units, convert to feet first (inches / 12, yards x 3, meters x 3.28084). For unit conversions: 1 cu ft = 1,728 cu in = 7.48 gal = 28.317 L.
Worked Examples
Example 1: Room Volume Calculation
Problem: Calculate the cubic footage of a room that is 12 feet long, 10 feet wide, and 8 feet high.
Solution: Volume = Length x Width x Height\nVolume = 12 ft x 10 ft x 8 ft = 960 cubic feet\n\nConversions:\nCubic yards: 960 / 27 = 35.56 cu yd\nCubic meters: 960 x 0.0283168 = 27.18 cu m\nLiters: 960 x 28.3168 = 27,184 liters\nGallons: 960 x 7.48052 = 7,181 gallons
Result: 960 cubic feet = 35.56 cubic yards = 27.18 cubic meters
Example 2: Shipping Box in Inches
Problem: A shipping box measures 24 inches long, 18 inches wide, and 16 inches high. What is the volume in cubic feet?
Solution: Convert to feet: 24/12 = 2 ft, 18/12 = 1.5 ft, 16/12 = 1.333 ft\nVolume = 2 x 1.5 x 1.333 = 4.0 cubic feet\n\nOr: Volume in cubic inches = 24 x 18 x 16 = 6,912 cu in\nConvert: 6,912 / 1,728 = 4.0 cubic feet\nGallons: 4.0 x 7.48 = 29.9 gallons
Result: 4.0 cubic feet = 6,912 cubic inches = 29.9 gallons
Frequently Asked Questions
What is a cubic foot and how is it measured?
A cubic foot is a unit of volume in the imperial and US customary measurement systems. It represents the volume of a cube with sides that each measure one foot in length, which equals 12 inches on each side. One cubic foot contains exactly 1,728 cubic inches (12 x 12 x 12) and equals approximately 7.48 US gallons or 28.317 liters. Cubic feet are commonly used in the United States for measuring shipping volumes, room sizes, refrigerator capacities, storage unit dimensions, concrete quantities, and HVAC airflow. To calculate cubic feet from dimensions, simply multiply length by width by height when all measurements are in feet.
How do you convert cubic inches to cubic feet?
To convert cubic inches to cubic feet, divide the number of cubic inches by 1,728. This conversion factor comes from cubing the linear relationship between inches and feet. Since there are 12 inches in one foot, and volume is a three-dimensional measurement, you must cube 12 to get the conversion factor: 12 x 12 x 12 = 1,728. For example, 5,000 cubic inches divided by 1,728 equals approximately 2.894 cubic feet. Conversely, to convert cubic feet to cubic inches, multiply by 1,728. This conversion is frequently needed when measuring oddly shaped objects in inches but needing the volume in cubic feet for shipping or storage calculations.
How do you calculate cubic feet for irregularly shaped objects?
For irregularly shaped objects, several methods can approximate cubic footage. The water displacement method involves submerging the object in a container of known dimensions and measuring how much the water level rises, then calculating the volume of displaced water. For objects that roughly approximate standard shapes, break them into simpler geometric components like cylinders, cones, and rectangles, calculate each volume separately, and add them together. For cylindrical objects, use pi times radius squared times height. For triangular cross-sections, use one-half times base times height times length. Professional applications often use 3D scanning or CAD software for precise volume measurements of complex shapes.
What is the difference between cubic feet and board feet?
Cubic feet and board feet are both volume measurements but used in different contexts. A cubic foot measures a three-dimensional space of one foot on each side. A board foot, used specifically in the lumber industry, measures a piece of wood one foot long, one foot wide, and one inch thick, equaling 144 cubic inches or exactly one-twelfth of a cubic foot. To convert board feet to cubic feet, divide by 12. Lumber is sold in board feet because wood thickness is standardized in nominal sizes like one inch, two inches, and four inches. Knowing both measurements helps when estimating how much lumber fits in a truck or storage space measured in cubic feet.
How many cubic feet are in common containers and spaces?
Understanding common volumes helps with practical estimation. A standard moving box is about 3 to 4.5 cubic feet. A typical refrigerator ranges from 18 to 25 cubic feet. A standard clothes dryer holds about 7 cubic feet. A 5x5x8 storage unit is 200 cubic feet. A standard 20-foot shipping container holds approximately 1,170 cubic feet. A full-size pickup truck bed holds about 50 to 80 cubic feet depending on the model. A typical bathtub holds about 13 cubic feet of water. A room measuring 10x12x8 feet contains 960 cubic feet. These reference points make it easier to visualize and estimate cubic footage for moving, storage, and construction projects.
What formula does Cubic Feet Calculator use?
The formula used is described in the Formula section on this page. It is based on widely accepted standards in the relevant field. If you need a specific reference or citation, the References section provides links to authoritative sources.