Cubic Feet Calculator

Free online cubic feet calculator for boxes, cylinders, pipes, cones, spheres, and pyramids. Enter your dimensions to get instant volume in cubic feet with unit conversions and cost estimates.

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What Is a Cubic Foot?

A cubic foot (cu ft or ft³) is a unit of volume equal to a cube that is 1 foot wide, 1 foot long, and 1 foot tall. It's one of the most commonly used volume measurements in the United States for construction, shipping, refrigeration, and home improvement projects.

Understanding cubic feet is essential for calculating the capacity of rooms, storage units, shipping containers, HVAC systems, and more. Our cubic feet calculator helps you quickly determine volume for 6 different shapes with instant unit conversions.

Quick Reference: 1 cubic foot = 1,728 cubic inches = 7.48 US gallons = 28.32 liters = 0.037 cubic yards = 0.0283 cubic meters
Common Uses: Refrigerator and freezer capacity, shipping box volume, room air volume for HVAC, concrete volume, water tank capacity, storage unit sizing

How to Calculate Cubic Feet

Box / Rectangle

Formula: Length ft × Width ft × Height ft = Cubic Feet

Example: A box that is 10 ft × 10 ft × 4 ft = 400 cubic feet

Cylinder (Round)

Formula: π × (Diameter/2)² × Height ft = Cubic Feet

Example: A tank 4 ft diameter × 6 ft tall = π × 2² × 6 = 75.4 cubic feet

Pipe / Hollow Cylinder

Formula: π × (OuterR² − InnerR²) × Length ft = Cubic Feet

Example: A pipe with 4 ft outer diameter, 3 ft inner diameter, 20 ft long = π × (2² − 1.5²) × 20 = 109.96 cubic feet

Cone

Formula: (1/3) × π × (Diameter/2)² × Height ft = Cubic Feet

Example: A cone with 6 ft base diameter × 8 ft tall = (1/3) × π × 3² × 8 = 75.4 cubic feet

Sphere

Formula: (4/3) × π × (Diameter/2)³ = Cubic Feet

Example: A sphere with 6 ft diameter = (4/3) × π × 3³ = 113.1 cubic feet

Pyramid

Formula: (1/3) × Base Length ft × Base Width ft × Height ft = Cubic Feet

Example: A pyramid with 6 ft × 4 ft base, 8 ft tall = (1/3) × 6 × 4 × 8 = 64 cubic feet

Cubic Feet Conversion Table

Unit1 Cubic Foot =1 Cubic Yard =
Cubic Inches1,728 cu in46,656 cu in
Cubic Yards0.037 cu yd1 cu yd
Cubic Meters0.0283 cu m0.765 cu m
Liters28.32 L764.6 L
Gallons (US)7.48 gal202 gal

Frequently Asked Questions

How do I calculate cubic feet from inches?
Divide each measurement in inches by 12 to convert to feet, then multiply length × width × height. For example, a box 24 in × 12 in × 12 in = 2 ft × 1 ft × 1 ft = 2 cubic feet. Our calculator handles this automatically — just enter inches separately.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in 1 cubic yard (3 ft × 3 ft × 3 ft = 27 cu ft). To convert cubic feet to cubic yards, divide by 27.
How do I calculate cubic feet for shipping?
Measure the length, width, and height of your package in inches, multiply them together, then divide by 1,728 to get cubic feet. For freight shipping, dimensional weight may also apply — check with your carrier.
How many gallons is 1 cubic foot of water?
1 cubic foot of water equals approximately 7.48 US gallons. A cubic foot of water weighs about 62.4 pounds. This is useful for calculating aquarium volume, water tank capacity, and pool water volume.
How many cubic feet is a standard refrigerator?
Standard refrigerators range from 20-26 cubic feet for the fresh food compartment, with an additional 4-6 cubic feet for the freezer. A typical 36-inch-wide French door refrigerator is about 22-26 cubic feet total.
How do I calculate cubic feet of a room?
Measure the length, width, and ceiling height of the room in feet, then multiply them together. For example, a 12 ft × 14 ft room with 8 ft ceilings = 12 × 14 × 8 = 1,344 cubic feet. This is useful for sizing air conditioners and fans.
What is the difference between square feet and cubic feet?
Square feet (sq ft) measure area in two dimensions (length × width). Cubic feet (cu ft) measure volume in three dimensions (length × width × height). Square feet tell you how much floor space you have; cubic feet tell you how much space is inside a container or room.
How many wheelbarrows are in a cubic foot?
A standard wheelbarrow holds about 3-6 cubic feet. This means 1 cubic foot is about 1/3 to 1/6 of a typical wheelbarrow load. For a full cubic yard (27 cu ft), you'd need about 5-9 wheelbarrow trips.