How to Calculate Box Volume
Box volume is the amount of space inside (or taken up by) a rectangular box. Measure the length, width and height in the same unit, then multiply them together. The result is in cubic units of whatever you measured in: inches give cubic inches, centimeters give cubic centimeters.
Here is the full calculation for a 12 × 10 × 5 inch box ordered in a quantity of 100:
Volume: 12 × 10 × 5 = 600 cubic inches
Cubic feet: 600 ÷ 1,728 = 0.3472 ft³
Order volume: 0.3472 × 100 = 34.72 ft³
CBM: 34.72 × 0.0283168466 ≈ 0.983 CBM
Liters: 0.983 × 1,000 ≈ 983 liters
The calculator above does these steps for you and keeps full precision until the final display, so small boxes don’t get rounded down to zero.
How to Calculate Cubic Feet of a Box
If you measure in inches, multiply length × width × height to get cubic inches, then divide by 1,728. That number comes from 12 × 12 × 12: a one-foot cube holds 1,728 cubic inches.
A box that holds 2,000 cubic inches is 2,000 ÷ 1,728 = 1.157 cubic feet. A 12 × 12 × 12 inch box is exactly 1 cubic foot. If you measured in centimeters, the calculator converts using the exact definition 1 inch = 2.54 cm, so a 30.48 cm cube also comes out to exactly 1 cubic foot.
How to Calculate CBM for Cartons
CBM means cubic meters, the unit freight forwarders and shipping lines use for sea and air cargo. Convert each dimension to meters and multiply. A carton measuring 40 × 30 × 25 cm is 0.40 × 0.30 × 0.25 = 0.03 CBM. For 200 cartons, the shipment is 0.03 × 200 = 6 CBM.
If you work in inches, calculate cubic feet first and multiply by 0.0283168466, since one cubic foot equals 0.0283168466 cubic meters.
Box Volume vs Box Capacity
Volume is a geometric number. Capacity is what you can actually fit. A box with 600 cubic inches of inside volume won’t hold 600 cubic inches of product, because products have shapes, need protection, and leave gaps. Inserts, void fill, bubble wrap and dividers all use space that the volume figure counts as available.
Use volume to compare boxes and plan freight. Use a physical sample, or your product’s dimensions plus clearance, to decide whether your product fits.
How to Calculate Total Shipment Volume
Multiply the volume of one box by the number of boxes. For 500 boxes at 12 × 10 × 5 inches, that is 600 × 500 = 300,000 cubic inches, or 173.61 cubic feet, or about 4.92 CBM.
Two things to keep in mind. First, this is the space the cartons themselves occupy; pallets, gaps and loading clearance add to it. Second, use the box’s outside dimensions for shipping volume, since that is the space it takes up on a truck or in a container.
How Much Space Will My Boxes Take in a Container?
There are two ways to estimate how many cartons fit in a shipping container, and they can give quite different answers.
The volume-based estimate takes the container’s volume, reduces it by a packing efficiency (85% is a common planning figure), and divides by the carton’s volume. For a 20 ft standard container with about 33.2 CBM, 85% gives 28.22 CBM of usable space. With 40 × 30 × 25 cm cartons at 0.03 CBM each, that suggests about 940 cartons.
The 3D orientation estimate counts how many whole cartons line up along the container’s inside length, width and height. Using typical 20 ft inside dimensions of 5.898 × 2.352 × 2.393 m, the same carton fits in a 14 × 7 × 9 grid: 882 cartons. It’s lower because the leftover space along each wall is too small for another full carton.
Neither number is a loading plan. Weight limits, palletization, door openings and how the cargo is braced all affect the real count, so confirm with your freight forwarder before you book.
Inside vs Outside Box Dimensions
Inside dimensions describe the usable space in the box, which is what matters when you’re fitting a product. Outside dimensions describe the space the box takes up, which is what matters for freight, pallets, warehouse storage and carrier billing.
The difference comes from board thickness and, for some styles, flaps and closures. A box with 12 × 10 × 5 inch inside dimensions might measure roughly 12.3 × 10.3 × 5.4 inches outside, depending on the material. That small change adds up: 684 cubic inches instead of 600, or about 14% more volume per box. When you request a custom box quote, say which set of dimensions you are giving.
Box Volume vs Dimensional Weight
Dimensional (DIM) weight is a pricing method, not a physical weight. Parcel carriers divide a package’s cubic inches by a DIM divisor to get a weight that reflects how much space the package uses, and then usually bill the higher of that number and the actual scale weight.
A 12 × 10 × 5 inch box with a divisor of 139 has a DIM weight of 600 ÷ 139 = 4.32 lb. If the packed box only weighs 1.5 lb, the carrier may still bill it as about 5 lb once rounding is applied. Divisors and rounding rules vary by carrier, service and contract, so check yours. Our Box Size & Dimensional Weight Calculator goes deeper on this.
How to Reduce Packaging Shipping Volume
Small changes in box size have a large effect at order scale. Trimming a 12 × 10 × 5 inch box to 12 × 10 × 4 inches cuts its volume by 20%, from 600 to 480 cubic inches. Across 1,000 units that saves 69.44 cubic feet, close to 2 CBM of freight space.
- Size the box to the product plus the protection it actually needs, not to the nearest stock size.
- Check the height first. It’s often the dimension with the most unused space.
- Use inserts that hold the product in place, so you need less void fill and a smaller box.
- Consider shipping flat-packed or nested where the product allows it.
- Compare sizes side by side with the box comparison tool above before ordering.
Custom-sized packaging is one of the most direct ways to do this. Send us your dimensions and we’ll help you find a size that protects the product without shipping air.
Box Volume Formulas
Geometric formulas (exact)
- Box volume
- L × W × H
- Cubic feet
- Cubic inches ÷ 1,728
- CBM
- Cubic feet × 0.0283168466
- Liters
- CBM × 1,000
- Cubic centimeters
- Cubic inches × 16.387064
- Total volume
- Single box volume × quantity
- Surface area
- 2 × (L×W + L×H + W×H)
Planning estimates (approximate)
- DIM weight
- L × W × H (inches) ÷ DIM divisor
- Effective container volume
- Container volume × packing efficiency
- Volume-based cartons per container
- Effective volume ÷ carton CBM, rounded down
- 3D cartons per container
- ⌊Length ÷ l⌋ × ⌊Width ÷ w⌋ × ⌊Height ÷ h⌋, best of each carton orientation
- Boxes per pallet
- Boxes per layer × ⌊max stack height ÷ box height⌋
Geometric formulas give exact answers for a perfect rectangle. Planning estimates depend on real-world conditions and should be confirmed before you commit to freight or storage.
Example Box Volume Reference
Volumes for a range of example box sizes, measured in inches. These are examples for comparison, not a list of standard industry sizes.
| Box size (in) | Cubic inches | Cubic feet | Liters | CBM |
|---|---|---|---|---|
| 6 × 4 × 2 | 48 | 0.0278 | 0.787 | 0.000787 |
| 8 × 6 × 3 | 144 | 0.0833 | 2.36 | 0.00236 |
| 10 × 8 × 4 | 320 | 0.185 | 5.24 | 0.00524 |
| 12 × 10 × 5 | 600 | 0.347 | 9.83 | 0.00983 |
| 14 × 10 × 6 | 840 | 0.486 | 13.77 | 0.0138 |
| 16 × 12 × 8 | 1,536 | 0.889 | 25.17 | 0.0252 |
| 18 × 18 × 18 | 5,832 | 3.375 | 95.57 | 0.0956 |
| 24 × 18 × 18 | 7,776 | 4.5 | 127.43 | 0.1274 |
Frequently Asked Questions
What is box volume?
Box volume is the three-dimensional space of a box, calculated as length × width × height. It’s a geometric measurement. On its own it doesn’t tell you how many products fit inside, the exact warehouse footprint, the exact pallet or container count, or the shipping price; those need more information.
How do I calculate cubic feet of a box?
Measure the box in inches, multiply length × width × height, and divide by 1,728. A 12 × 10 × 5 inch box is 600 ÷ 1,728 = 0.347 cubic feet.
How many cubic feet are in a box?
It depends entirely on the box size. A 12 × 12 × 12 inch box is exactly 1 cubic foot, an 18 × 18 × 18 inch box is 3.375 cubic feet, and a small 6 × 4 × 2 inch mailer is only 0.0278 cubic feet. Enter your dimensions in the calculator for your exact figure.
How do I calculate CBM for a carton?
Convert the carton’s length, width and height to meters and multiply them. A 40 × 30 × 25 cm carton is 0.4 × 0.3 × 0.25 = 0.03 CBM. Multiply by the number of cartons to get the shipment CBM.
How do I convert cubic inches to cubic feet?
Divide cubic inches by 1,728. For example, 3,456 cubic inches ÷ 1,728 = 2 cubic feet.
How do I calculate total volume for 100 boxes?
Calculate the volume of one box and multiply by 100. One 12 × 10 × 5 inch box is 0.3472 cubic feet, so 100 boxes are 34.72 cubic feet, or about 0.983 CBM.
Should I use inside or outside dimensions?
Use inside dimensions when you need to know what the box can hold. Use outside dimensions for freight, pallets, warehouse storage, container planning and carrier DIM weight, since those depend on the space the box takes up.
What is the difference between cubic feet and CBM?
Both measure volume. Cubic feet (ft³) is common in the US for parcel, warehouse and trucking work. CBM (cubic meters, m³) is the standard for international freight. One CBM equals about 35.31 cubic feet, and one cubic foot equals 0.0283 CBM.
Can box volume tell me how much product fits inside?
Not reliably. Products rarely fill a box perfectly, and inserts, padding and void fill take up space. Compare your product’s dimensions with the box’s inside dimensions and allow for the protection it needs.
What is dimensional weight?
Dimensional weight is a billing weight carriers calculate from package size: length × width × height divided by a DIM divisor. Carriers typically charge the higher of dimensional weight and actual weight. Divisors and rounding rules vary, so confirm them with your carrier.
Does box volume equal shipping weight?
No. Volume measures space and weight measures mass. A large box of pillows and a small box of metal parts can have the same weight but very different volumes. Weigh your packed boxes to get the actual weight; DIM weight is a separate, size-based pricing figure.
How many boxes fit in a container?
As a rough guide, divide the container’s usable volume by one box’s CBM. A 20 ft standard container is often planned at about 33.2 CBM and a 40 ft high cube at about 76.4 CBM, before any packing efficiency. The calculator’s container planner also runs a simple 3D check using carton and container dimensions, which is usually more realistic. Your freight forwarder can confirm the final number.
Why is actual container loading lower than theoretical volume?
Cartons are rigid rectangles, so the space left along each wall is often too small for another carton. Pallets add height and gaps, weight limits can stop you before the container is full, and cargo needs room for loading, bracing and airflow. That’s why planners use a packing efficiency below 100% and why a 3D estimate is often lower than a volume estimate.