Cubic Feet Calculator
Calculate cubic feet instantly for any shape — box, cylinder, cone, or sphere. Enter dimensions in feet, inches, yards, meters, or cm. Includes multi-room totals and material cost estimator.
From inches: (L × W × H) ÷ 1,728
From meters: (L × W × H) × 35.315
From cm: (L × W × H) ÷ 28,316.8
1 ft³ = 1,728 in³ = 0.0283 m³ = 7.481 gallons = 28.317 liters
Cubic Feet Calculator - Calculate Volume for Any Shape
Calculate cubic feet instantly with our free calculator covering five calculation types: box or room volume, cylinder volume, cone volume, sphere volume, and combined multi-room totals. Cubic footage calculations come up constantly in everyday life: moving truck sizing (a 1-bedroom apartment needs roughly 650-800 cubic feet of truck space), refrigerator shopping (compare interior cubic feet between models), concrete and soil orders (a 10ft × 10ft × 0.5ft patio slab needs 50 cubic feet of concrete), shipping calculations (carriers charge by dimensional weight based on cubic footage), and aquarium or storage tank sizing. Our calculator shows the formula used for every result so you understand the math, not just the answer.
5 Types of Cubic Feet Problems - Which One Do You Need?
Type 1 - Box or Room: Most common. Used for rooms, boxes, storage units, and any rectangular space. Formula: Volume equals Length multiplied by Width multiplied by Height. Example: A storage unit measuring 10ft × 8ft × 8ft equals 640 cubic feet. Type 2 - Cylinder: Used for tanks, pipes, drums, and round pools. Formula: Volume equals pi multiplied by radius squared multiplied by height. Example: A cylindrical tank 4 ft in diameter and 6 ft tall equals pi × 2² × 6 equals 75.4 cubic feet. Type 3 - Cone: Used for piles of material like gravel, sand, or mulch. Formula: Volume equals one-third multiplied by pi multiplied by radius squared multiplied by height. Example: A gravel pile with a 6 ft base diameter and 4 ft tall equals (1/3) × pi × 3² × 4 equals 37.7 cubic feet. Type 4 - Sphere: Used for balls, spherical tanks, and dome structures. Formula: Volume equals four-thirds multiplied by pi multiplied by radius cubed. Example: A sphere 5ft diameter equals (4/3) × pi × 2.5³ equals 65.4 cubic feet. Type 5 - Multi-Room: Add multiple boxes or rooms together for a combined total — essential for moving estimates and whole-house material orders.
Real-World Cubic Feet Calculations That Matter
Moving truck sizing: A studio apartment needs approximately 150-300 cubic feet of truck space. A 1-bedroom needs 650-800 cubic feet. A 3-bedroom house needs 1,200-1,600 cubic feet. Underestimating means a second trip; overestimating means paying for unused truck space. Concrete orders: A driveway slab 20 ft × 10 ft × 0.33 ft (4 inches thick) equals 66 cubic feet, which converts to 2.4 cubic yards. Concrete is typically ordered by the cubic yard, so divide your cubic feet result by 27. Refrigerator comparison: A refrigerator listed as "25 cubic feet" refers to interior storage volume. Measuring interior height × width × depth in inches and dividing by 1,728 confirms manufacturer specifications. Shipping costs: Many carriers calculate dimensional weight using length × width × height in inches ÷ 139 for domestic shipments; knowing your cubic footage helps predict shipping costs before checkout. Soil and mulch: A garden bed 12 ft × 4 ft requiring 6 inches (0.5 ft) of new soil needs 24 cubic feet, which most garden centers sell by the cubic foot bag (typically 1.5 cubic feet per bag) or in bulk by the cubic yard.
Cubic Feet vs Cubic Yards - Common Confusion
These two units are related but easily confused, especially for construction materials like concrete, mulch, and soil. One cubic yard equals 27 cubic feet (3 ft × 3 ft × 3 ft). Materials sold in bulk (concrete, gravel, mulch, and topsoil) are almost always priced and delivered by the cubic yard, not cubic foot, because cubic yard quantities are large enough to be practical for trucking. Example: You calculate you need 81 cubic feet of mulch for your garden beds. Converting to cubic yards: 81 ÷ 27 equals 3 cubic yards; this is the number you give the supplier. A common mistake is ordering "3 cubic feet" when you meant "3 cubic yards" (which is 81 cubic feet), a 27x difference that results in a massively undersized delivery. Always double-check which unit a supplier is quoting before placing a bulk material order.
How to Measure for Accurate Cubic Feet Calculations
Measuring tips for accurate results. For rooms: measure wall-to-wall at floor level, not at the widest point if walls are angled. For irregular rooms: split them into rectangular sections, calculate each separately, then add them together using the Multi-Room tab. For cylindrical containers: measure diameter at the widest point, not the narrowest; many containers taper slightly. For material piles (gravel, sand, mulch): the cone calculator assumes a roughly conical pile shape, which is typical for poured material. Measure base diameter and peak height. For shipping boxes, always measure to the nearest whole inch and round up slightly to account for packing material. For refrigerators and appliances: use interior dimensions for storage capacity calculations and exterior dimensions for fitting through doorways and into spaces.
Frequently Asked Questions About Cubic Feet
Q: How do I calculate cubic feet of a room?
A: Multiply length × width × height, all measured in feet. Example: A room 12 ft long, 10 ft wide, and 8 ft ceiling height equals 12 × 10 × 8 equals 960 cubic feet. If your measurements are in inches, divide the final answer by 1,728 to convert to cubic feet.
Q: How many cubic feet are in a cubic yard?
A: There are 27 cubic feet in one cubic yard (3 ft × 3 ft × 3 ft equals 27 cubic feet). To convert cubic feet to cubic yards, divide by 27. To convert cubic yards to cubic feet, multiply by 27. This conversion matters most for concrete, mulch, and soil orders, which are typically priced by the cubic yard.
Q: How do I calculate cubic feet from inches?
A: Measure length, width, and height in inches, multiply all three together to get cubic inches, then divide by 1,728 (which is 12³) to convert to cubic feet. Example: A box 24 in × 18 in × 12 in equals 5,184 cubic inches divided by 1,728 equals 3 cubic feet.
Q: How many cubic feet is a standard refrigerator?
A: Standard refrigerators range from 18 to 25 cubic feet of total interior capacity. Compact refrigerators are typically 4-9 cubic feet. Side-by-side and French door models commonly range 22-28 cubic feet. The cubic footage refers to interior storage space, not the appliance's exterior dimensions.
Q: How do I calculate cubic feet for moving?
A: Add up the cubic footage of major furniture and boxes, or use standard estimates: studio apartments need approximately 150-300 cubic feet of truck space, 1-bedroom apartments need 650-800 cubic feet, 2-bedroom homes need 900-1,200 cubic feet, and 3-bedroom homes need 1,200-1,600 cubic feet. Use the Multi-Room tab to add up individual large items for a precise total.
Q: What is the formula for cubic feet of a cylinder?
A: Cubic feet of a cylinder equals pi multiplied by radius squared multiplied by height, where radius equals diameter divided by 2. Example: A cylinder 3ft in diameter and 8ft tall has a radius of 1.5ft, so volume equals 3.14159 × 1.5² × 8 equals 56.5 cubic feet.