📦 Cubic Feet Calculator: Find Volume in Cubic Feet Fast
By Shihab Mia · Updated 2026-07-06
Volume = length x width x height, with every side converted to feet first.
This cubic feet calculator finds the volume of any box-shaped space from its length, width, and height using the formula volume = length x width x height. Pick your measurement unit (feet, inches, centimeters, or meters) and the tool converts every side to feet before multiplying, so the answer is always correct cubic feet. It also reports the same volume in cubic yards, cubic meters, US gallons, and liters, and lets you multiply by a quantity to total several identical boxes at once.
What is the Cubic Feet Calculator?
Cubic feet (ft3) is a measure of volume, the amount of three-dimensional space inside an object or room. For any rectangular box, container, or room the formula is simply volume = length x width x height, with all three measurements in feet. A crate that is 4 feet long, 3 feet wide, and 2 feet high holds 4 x 3 x 2 = 24 cubic feet. The single most important rule is that all three sides must be in the same unit before you multiply, which is why this calculator converts your inputs to feet behind the scenes whenever you switch units.
Measurements rarely arrive already in feet. Shipping boxes and appliances are labeled in inches, soil and gravel bags are sized in liters or cubic meters, and furniture specs are often metric. To turn inches into cubic feet you can convert each side by dividing by 12, or, more simply, multiply the three side lengths together in inches and divide that product by 1728. The number 1728 is just 12 x 12 x 12, the count of cubic inches in one cubic foot. For centimeters there are 30.48 cm in a foot, and for meters there are 0.3048 m in a foot, so this tool applies the right factor automatically.
Not every object is a rectangular box. For a cylinder such as a barrel, tank, or round planter, the volume is pi x radius squared x height. Work in inches, then divide by 1728 to get cubic feet. For example, a drum with a 9 inch radius and a 33 inch height holds about 3.14159 x 9 x 9 x 33 = 8397 cubic inches, which is 8397 divided by 1728 = about 4.86 cubic feet. For any irregular shape, break the object into rectangular blocks or cylinders, calculate each piece on its own, and add the results together for the grand total.
Once you have the volume in cubic feet, several related units are often handy. Cubic yards are used for ordering concrete, gravel, mulch, and topsoil in the US, and there are 27 cubic feet in one cubic yard, so divide cubic feet by 27. Cubic meters are the metric standard for international shipping and freight, and one cubic foot equals about 0.0283 cubic meters. For liquids, one cubic foot holds about 7.48 US gallons or 28.32 liters. The calculator reports all of these at once so you can read whichever unit your supplier, carrier, or spec sheet expects.
Cubic feet is also central to freight and moving costs. Carriers charge by the space a shipment occupies, so density (weight in pounds divided by volume in cubic feet) sets the freight class for LTL shipments. When you calculate cubic feet for shipping, always round each dimension up to the next whole inch before multiplying and measure the outside of the packaging, not just the item inside, because carriers do exactly that and rounding down can trigger a billing correction. For a full house move, the total cubic footage of all boxes and furniture estimates the truck size and van space you will need.
Real projects often involve more than one identical container or a repeated shape, such as a stack of boxes, a row of raised beds, or a pallet of cartons. Use the optional quantity field to multiply a single computed volume by the number of identical items, giving a fast total without repeating the math. For landscaping, remember that bagged material is usually sold by volume, so converting your bed area and depth into cubic feet tells you exactly how many bags or cubic yards to order.
When to use it
- Working out the volume of a moving box, crate, or storage unit before a move or shipment.
- Ordering soil, mulch, gravel, or concrete by converting cubic feet to cubic yards for landscaping.
- Checking the interior capacity of a refrigerator, freezer, microwave, or oven in cubic feet.
- Calculating freight cubic footage and density to estimate LTL shipping class and cost.
- Sizing an aquarium, water tank, or barrel and converting the result to gallons or liters.
- Estimating room volume in cubic feet for HVAC airflow, duct sizing, or air purifier coverage.
How to use the Cubic Feet Calculator
- Choose the unit your measurements are in: feet, inches, centimeters, or meters.
- Measure and enter the length, width, and height of the box or space.
- Optionally set a quantity to multiply the volume by several identical items.
- Read the volume in cubic feet, cubic yards, cubic meters, and gallons, then click Copy result to save it.
Formula & method
Worked examples
A storage crate measured in feet: 4 ft long, 3 ft wide, 2 ft high.
- volume = length x width x height
- volume = 4 x 3 x 2 = 24 cubic feet
- in cubic yards: 24 divided by 27 = 0.889 yd3
- in cubic meters: 24 x 0.0283168466 = 0.679 m3
Result: 24 cubic feet (about 0.889 yd3 or 0.679 m3)
A shipping box measured in inches: 24 in long, 18 in wide, 12 in high.
- multiply the sides in inches: 24 x 18 x 12 = 5184 cubic inches
- divide by 1728 to convert to cubic feet: 5184 divided by 1728 = 3
- so the box is 3 cubic feet
Result: 3 cubic feet
A cylindrical barrel measured in inches: 9 in radius, 33 in high.
- volume of a cylinder = pi x radius x radius x height
- volume = 3.14159 x 9 x 9 x 33 = 8397 cubic inches
- divide by 1728 to convert to cubic feet: 8397 divided by 1728 = 4.86
- so the barrel holds about 4.86 cubic feet (about 36.3 US gallons)
Result: about 4.86 cubic feet (roughly 36.3 gallons)
Common volume unit conversions
| From | To | Multiply by |
|---|---|---|
| Cubic inches (in3) | Cubic feet (ft3) | divide by 1728 |
| Cubic feet (ft3) | Cubic yards (yd3) | divide by 27 |
| Cubic feet (ft3) | Cubic meters (m3) | 0.0283168466 |
| Cubic meters (m3) | Cubic feet (ft3) | 35.3147 |
| Cubic feet (ft3) | US gallons | 7.48052 |
| Cubic feet (ft3) | Liters | 28.3168 |
How each input unit converts to one foot
| Input unit | In one foot | Side factor to feet |
|---|---|---|
| Inches | 12 inches | divide by 12 |
| Centimeters | 30.48 cm | divide by 30.48 |
| Meters | 0.3048 m | divide by 0.3048 |
| Feet | 1 foot | no change |
Typical cubic feet capacity of everyday items (approximate)
| Item | Typical size | Approx. cubic feet |
|---|---|---|
| Countertop microwave | compact to mid-size | 0.7 to 2.2 ft3 |
| Full-size refrigerator | household | 18 to 26 ft3 |
| Chest freezer | small to large | 5 to 25 ft3 |
| Standard moving box | medium 18x18x16 in | about 3.0 ft3 |
| Bag of mulch | common retail bag | 2 ft3 |
| 55-gallon drum | industrial barrel | about 7.35 ft3 |
Common mistakes to avoid
- Forgetting to divide inches by 1728. Multiplying three sides in inches gives cubic inches, not cubic feet. Divide that product by 1728 (or convert each side to feet first) to get the correct cubic feet.
- Mixing units between the three sides. A length in feet times a width in inches gives a meaningless result. Convert all three measurements to the same unit before multiplying. This tool keeps every side in one unit for you.
- Confusing cubic feet with square feet. Square feet measure flat area (length x width). Cubic feet measure volume and need a third dimension, the height. Do not use an area figure where a volume is required.
- Dividing cubic feet by the wrong number for cubic yards. There are 27 cubic feet in a cubic yard, not 3 or 9. A yard is 3 feet, but a cubic yard is 3 x 3 x 3 = 27 cubic feet, so divide cubic feet by 27.
- Rounding shipping dimensions down instead of up. For freight and parcel shipping, always round each dimension up to the next whole inch and measure the outer packaging. Carriers round up, so rounding down under-reports volume and can trigger a billing correction.
- Using the diameter instead of the radius for a cylinder. The cylinder formula uses radius squared, and the radius is half the diameter. Plugging in the full diameter overstates the volume by a factor of four, so halve the diameter first.
Glossary
- Cubic foot (ft3)
- A unit of volume equal to a cube one foot on every side. It is the standard volume unit for storage, appliances, and shipping in the US.
- Volume
- The amount of three-dimensional space an object occupies, found for a box by multiplying length, width, and height.
- Cubic yard (yd3)
- A cube three feet on every side, equal to 27 cubic feet. Used to order concrete, gravel, soil, and mulch.
- Cubic meter (m3)
- The metric unit of volume, a cube one meter on each side. One cubic meter equals about 35.31 cubic feet.
- 1728
- The number of cubic inches in one cubic foot, equal to 12 x 12 x 12. Divide cubic inches by 1728 to get cubic feet.
- Quantity multiplier
- A count of identical items used to scale a single computed volume, so several equal boxes can be totaled at once.
- Density (freight)
- A shipment weight in pounds divided by its volume in cubic feet. LTL carriers use density to assign freight class and set the rate.
- Dimensional weight
- A billing weight based on package volume rather than actual weight, used by carriers when a box is large but light.
Frequently asked questions
How do I calculate cubic feet?
Multiply length by width by height with all three measured in feet. For example, a 4 ft by 3 ft by 2 ft box is 4 x 3 x 2 = 24 cubic feet. This calculator does the multiplication and unit conversion for you.
How do I find cubic feet from inches?
Multiply the three sides in inches, then divide by 1728. For example, 24 x 18 x 12 = 5184 cubic inches, and 5184 divided by 1728 = 3 cubic feet. Select Inches in the tool and it divides by 1728 automatically.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in one cubic yard, because a yard is 3 feet and 3 x 3 x 3 = 27. To convert cubic feet to cubic yards, divide by 27. The calculator shows both figures at once.
How do I convert cubic feet to cubic meters?
Multiply cubic feet by 0.0283168466 to get cubic meters, or divide by 35.3147. For example, 24 cubic feet x 0.0283168466 is about 0.679 cubic meters. This tool reports cubic meters alongside cubic feet.
How many gallons are in a cubic foot?
One cubic foot holds about 7.48 US gallons or 28.32 liters. To convert cubic feet to gallons, multiply by 7.48052. For example, a 5 cubic foot tank holds about 37.4 US gallons.
What is the difference between cubic feet and square feet?
Square feet measure area, a flat surface (length x width). Cubic feet measure volume and include a third dimension, height (length x width x height). Use cubic feet whenever you need the space inside a box or room.
How do I calculate cubic feet of a cylinder?
Use volume = pi x radius x radius x height. Measure in inches, then divide by 1728 for cubic feet. For a barrel with a 9 inch radius and 33 inch height: 3.14159 x 9 x 9 x 33 = 8397 cubic inches, divided by 1728 is about 4.86 cubic feet.
How do I calculate cubic feet for shipping?
Measure the outer packaging length, width, and height in inches, round each up to the next whole inch, multiply them, and divide by 1728. Carriers use this volume, along with weight, to set freight density and class.
How do I calculate the volume of an irregular shape?
Split the object into rectangular blocks and cylinders, calculate the cubic feet of each piece separately, and add the results together. For repeated identical shapes, use the quantity field to multiply one volume by the count.
How many cubic feet is a standard moving box?
A common medium moving box (about 18 x 18 x 16 inches) is roughly 3 cubic feet. Small boxes run near 1.5 cubic feet and large boxes near 4.5 cubic feet, so total the boxes to estimate truck space.