Cubic Feet Calculator

How to calculate cubic feet

Measure length, width, and height in one unit system, convert every side to feet, then multiply. The same steps cover how to figure, measure, and determine cubic feet for a room, box, or container.

1. Measure the interior length, width, and height of the space you fill. Use a tape on the cavity, not the exterior shell.
2. Convert every dimension to feet before you multiply. Inches ÷ 12; yards × 3; meters × 3.28084; centimeters ÷ 30.48. Feet+inches: convert inches to feet (÷12), then add the feet.
3. Multiply length × width × height in feet. The product is cubic feet (ft³). Example: 10 × 8 × 8 = 640 cubic feet.
4. Determine cubic feet from all-inch measurements by multiplying in inches, then dividing cubic inches by 1,728 (12 × 12 × 12).
5. Figure totals for identical items by multiplying one item volume by quantity, or enter quantity in the calculator after choosing a shared unit for all sides.

The calculator returns cubic feet to 2 decimals, with cubic yards, cubic meters, and US gallons in parentheses. Shared unit mode covers feet, inches, feet+inches, yards, meters, and centimeters.

Cubic feet formula

Cubic feet equal length × width × height when all three dimensions are in feet.

Cubic Feet = Length (ft) × Width (ft) × Height (ft)

A raised garden bed measuring 12 feet long, 6 feet wide, and 6 inches (0.5 ft) deep holds 12 × 6 × 0.5 = 36 cubic feet (1.02 m³) of soil. The formula stays identical for any box-shaped space: a room, a truck bed, a freezer, a concrete slab, or a shipping crate.

Three measurements are all the formula needs: length, width, and height. Two details decide whether the result is right:

• Measure the space you fill, not the object's shell. Refrigerator capacity comes from the interior length, width, and depth, not the exterior dimensions of the cabinet.
• Convert every dimension to the same unit before multiplying. Multiplying 12 feet by 6 inches without converting produces a meaningless number. Convert 6 inches to 0.5 feet first, then multiply.

Calculate Cubic Feet from Meters

Calculate cubic feet from meters in 2 steps:

1. Multiply length × width × height in meters. The result is cubic meters (m³), the unit shipping companies call CBM.
2. Multiply the total by 35.3147, since one cubic meter equals 35.3147 cubic feet (or multiply by 0.0283168 to go from ft³ to m³).

Example: a pallet load measures 1.2 m × 1.0 m × 1.5 m. Multiply: 1.2 × 1.0 × 1.5 = 1.8 m³. Convert: 1.8 × 35.3147 = 63.57 cubic feet.

Calculate Cubic Feet from Yards

Calculate cubic feet from yards in 2 steps:

1. Multiply length × width × height in yards. The result is cubic yards (yd³).
2. Multiply the total by 27, since one cubic yard contains 27 cubic feet (3 × 3 × 3).

Example: a topsoil delivery of 2 cubic yards equals 2 × 27 = 54 cubic feet, enough to fill a 12 ft × 9 ft bed 6 inches deep.

Calculate Cubic Feet from Centimeters

Calculate cubic feet from centimeters in 2 steps:

1. Multiply length × width × height in centimeters. The result is cubic centimeters (cm³).
2. Divide the total by 28,316.8466, since one cubic foot equals 0.0283168 m³ (28,316.8466 cm³).

Example: a suitcase measures 75 cm × 50 cm × 30 cm. Multiply: 75 × 50 × 30 = 112,500 cm³. Divide: 112,500 ÷ 28,316.8466 = 3.97 cubic feet.

How to calculate cubic feet from inches

Calculate cubic feet from inches in 2 steps:

1. Multiply length × width × height in inches. The result is cubic inches (in³).
2. Divide the total by 1,728, since one cubic foot contains 1,728 cubic inches (12 × 12 × 12).

Example: a refrigerator interior measures 64 in × 28 in × 29 in. Multiply: 64 × 28 × 29 = 51,968 cubic inches. Divide: 51,968 ÷ 1,728 = 30.07 cubic feet (851 liters).

Calculate Cubic Feet of a Rectangle

The cubic feet of a rectangle (rectangular prism) equal length × width × height. The rectangle is the shape people measure most: rooms, moving boxes, pallets, mattresses, aquariums, drawers, crates, and slabs are all rectangular prisms. Measure the three sides, convert them to feet, and multiply.

Worked example: a storage crate measures 4 ft long, 2.5 ft wide, and 2 ft tall. Multiply: 4 × 2.5 × 2 = 20 cubic feet (0.57 m³ / 149.6 US gallons). At a freight rate of $0.85 per cubic foot, the crate costs 20 × 0.85 = $17.00 to ship.

A cube is a rectangle with three equal sides, so its volume equals side³. A 3-foot cube holds 3³ = 27 cubic feet , exactly one cubic yard. The Box / Rectangular Cubic Feet Calculator adds quantity and cost fields for multi-box counts. Box / Rectangular Cubic Feet Calculator

Calculate Cubic Feet of an Irregular Shape

Calculate an irregular shape in 3 steps: divide the shape into regular rectangles, calculate the cubic feet of each rectangle, and add the volumes together.

Worked example , an L-shaped cabinet: the long section measures 2 ft × 3 ft × 6 ft = 36 cubic feet. The short section measures 2 ft × 3 ft × 2 ft = 12 cubic feet. Added together, the cabinet holds 36 + 12 = 48 cubic feet (1.36 m³).

The same split-and-add method measures L-shaped rooms, car trunks with wheel arches, alcoves, and stepped foundations. Rounded or tapered sections use the cylinder or cone formula for that piece, then join the total. The Irregular Shape Cubic Feet Calculator holds up to 6 sections and adds them automatically. Irregular Shape Cubic Feet Calculator

Cubic Feet Formulas for Common Shapes

There are 11 volume formulas that cover the shapes people measure, with all dimensions in feet:

What is a Cubic Foot?

A cubic foot is the volume of a cube measuring 1 foot (12 inches or 30.48 centimeters) on each side: length, width, and height. The symbol for cubic foot is ft³, and common abbreviations include cu ft and CFT. A cubic foot calculator and a cft calculator both use this unit. The cubic foot is a standard unit of volume in the United States and the United Kingdom.

One cubic foot equals 1,728 cubic inches, 0.037 cubic yards, 0.0283 cubic meters, 28.317 liters, 29.922 US quarts, and 7.481 US gallons.

For a physical reference, a standard file box (15 in × 12 in × 10 in) holds 1.04 cubic feet , picture one file box and you picture one cubic foot. A basketball occupies about 0.25 cubic feet, a dishwasher interior about 5 cubic feet, and a 10 ft × 10 ft room with 8-foot ceilings exactly 800 cubic feet.

Cubic feet measure 3-dimensional space; square feet measure a 2-dimensional plane. Multiplying length × width gives a flat area, the way a sheet of poster paper covers a floor. Multiplying that area by height adds the third dimension and produces volume , a room of air, a tank of water, a bed of soil.

Why Measure Cubic Feet?

How to measure cubic feet: take interior length, width, and height in the same unit, then multiply. People measure cubic feet for 6 main reasons: moving, freight shipping, landscaping, construction, appliance sizing, and HVAC planning.

1. Moving and storage , movers quote by load volume, and storage facilities size units in cubic feet.
2. Freight shipping , LTL freight class, USPS Cubic pricing, and UPS dimensional weight all start from cargo volume in cubic feet.
3. Landscaping , mulch, gravel, soil, and sand sell by the cubic foot (bags) or cubic yard (bulk delivery).
4. Construction , concrete slabs, insulation, and timber are ordered by volume. An 80 lb (36 kg) bag of concrete mix yields 0.6 cubic feet; a 60 lb (27 kg) bag yields 0.45 cubic feet.
5. Appliance sizing , refrigerator capacity, freezer space, washer drums, and microwave interiors are all rated in cubic feet.
6. HVAC and ventilation , air conditioner BTUs, furnace output, and duct airflow (measured in cubic feet per minute, CFM) follow room air volume.

Calculate Cubic Feet for Moving

Calculate cubic feet for moving by measuring each box and furniture piece, then adding the volumes together. Standard moving boxes come in 5 sizes: extra small (1 cu ft), small (1.5 cu ft), medium (3 cu ft), large (4.5 cu ft), and extra large (6 cu ft).

Worked example , sizing a storage unit: you have 10 small boxes (16 × 12 × 12 in), 8 medium boxes (18 × 18 × 16 in), and 5 large boxes (24 × 18 × 18 in).

1. Calculate cubic inches per box type: small = 2,304 in³, medium = 5,184 in³, large = 7,776 in³.
2. Convert each to cubic feet (÷ 1,728): small = 1.33 cu ft, medium = 3.0 cu ft, large = 4.5 cu ft.
3. Multiply by quantity: 10 × 1.33 = 13.3, 8 × 3.0 = 24, 5 × 4.5 = 22.5.
4. Add the totals: 13.3 + 24 + 22.5 = 59.8 cubic feet.

A 60 cubic-foot unit fits the boxes with zero walking space, so rent the next size up. Movers add 10 to 15% to raw furniture volume for packing gaps and void fill. Total your inventory with the Moving Cubic Feet Calculator, then match the figure to a unit with the Storage Unit Calculator. Moving Cubic Feet Calculator · Storage Unit Cubic Feet Calculator · door frame opening volume

Calculate Cubic Feet for Landscaping Material (Mulch, Gravel, Soil)

Calculate landscaping material by multiplying bed length × width × depth, with depth converted to feet.

Worked example , mulching a flower bed: the bed measures 20 ft long and 8 ft wide, and the target depth is 3 inches.

1. Convert the depth: 3 in ÷ 12 = 0.25 ft.
2. Multiply: 20 × 8 × 0.25 = 40 cubic feet of mulch.
3. Convert to bags: most mulch bags hold 2 cubic feet, so 40 ÷ 2 = 20 bags.
4. Convert to bulk: 40 ÷ 27 = 1.48 cubic yards for a bulk delivery quote.

Add 5 to 10% for settling and waste , organic mulch compacts within weeks, and soil settles after watering. Bagged soil typically holds 1.5 cubic feet per bag, gravel 0.5 cubic feet per 50 lb (22.7 kg) bag. The Mulch, Gravel, Soil, and Raised Bed calculators return bag counts and cost totals directly. Mulch Cubic Feet Calculator · Gravel Cubic Feet Calculator · Soil Cubic Feet Calculator · Raised Bed Cubic Feet Calculator · timber and log CFT

Real-World Examples

Two worked scenarios show the calculator solving everyday comparisons.

Example 1 , comparing two boxes. A toy box for a child's room comes in two sizes that look similar on the shelf. Box A measures 70 × 30 × 30 inches: 70 × 30 × 30 = 63,000 in³ ÷ 1,728 = 36.46 cubic feet. Box B measures 60 × 28 × 45 inches: 75,600 in³ ÷ 1,728 = 43.75 cubic feet. Box B holds 7.29 cubic feet more , a 20% capacity advantage invisible to the eye.

Example 2 , an L-shaped car trunk. A trunk wraps around a wheel arch, forming two rectangles. The main section measures 60 × 30 × 35 in = 63,000 in³ = 36.46 cu ft. The side section measures 18 × 14 × 35 in = 8,820 in³ = 5.10 cu ft. Added together, the trunk holds 36.46 + 5.10 = 41.56 cubic feet , the number to check against furniture-in-a-box dimensions before a store trip.

Convert cubic feet to other units

Use the factors below to convert cubic feet to inches, yards, meters, gallons, and liters.

Common measuring mistakes

The biggest measuring mistake is mixing units without converting them first. Multiplying 12 feet by 6 inches as if both were feet produces a wrong volume. Convert every dimension to feet (6 inches = 0.5 ft), then multiply length × width × height.

A close second is measuring the exterior shell instead of the interior space you fill. Refrigerator capacity, raised beds, and storage crates use interior length, width, and height. Measure the fill cavity, not the cabinet or frame.

Key Takeaways

• Multiply length × width × height in feet to get cubic feet.
• Convert inch measurements by dividing cubic inches by 1,728.
• Use interior dimensions for capacity, not exterior shells.
• Divide cubic feet by 27 to convert to cubic yards.
• Enter mixed units in the calculator; it converts before multiplying.

Conclusion

Open the cubic feet calculator above, enter length × width × height, and convert as needed with tools such as brass to cubic feet and cubic feet to kWh.

Learn the unit itself in what a cubic foot is, measure refrigerator capacity in cubic feet, browse all volume guides, or send feedback to the team.