How do I calculate dimensional weight?

Multiply the outside length, width and height of the package, then divide the cubic size by the applicable DIM divisor. Carrier rules commonly require rounding dimensions and the final weight.

Is billable weight actual or dimensional weight?

Carriers commonly compare actual scale weight with dimensional weight and rate the package using the greater value, subject to service-specific rules and surcharges.

Is this dimensional weight calculator online free?

Yes. It is free, requires no account and performs calculations locally in your browser.

Pack smarter, estimate clearly

Shipping Box Dimensional Weight Calculator

Q: What is dimensional weight?

Dimensional weight, also called DIM or volumetric weight, converts the space a package occupies into a weight used for shipping-rate calculations.

Q: What DIM divisor should I use?

Use the divisor published for your carrier, service, country and account. Common examples include 139 cubic inches per pound, 166 cubic inches per pound and 5,000 cubic centimeters per kilogram.

Enter a box's outside measurements and scale weight. Instantly compare DIM weight with actual weight and see which one may determine your shipping charge.

Free to useNo sign-upCalculated in your browser

Your estimate

Estimated billable weight

DIM applies

Use the greater weight14 lb

Dimensional weight is higher than the 3 lb scale weight.

Actual weight3 lb

Dimensional weight14 lb

Calculation 16 × 12 × 10 ÷ 139 = 13.81 lb Rounded up to 14 lb for the billable-weight comparison.

You may be paying to ship air

DIM weight adds 11 lb above the box's scale weight. A snugger box could lower the rated weight.

Estimate only. Carrier rounding, service rules, minimums, oversize charges and account terms can change the final billed weight and price.

How to calculate dimensional weight

Dimensional weight—also called DIM weight, volumetric weight or cubed weight—represents how much space a package occupies relative to its actual weight.

Measure outside edges

Measure length, width and height at the box's widest points. Include bulges and protrusions.

Find cubic size

Multiply the three measurements: length × width × height.

Divide by the DIM factor

Use the divisor assigned to your carrier, service, country and account.

Compare both weights

The greater of actual and rounded DIM weight is commonly used as the billable weight.

Common dimensional weight divisors

There is no single divisor for every shipment. Published factors vary by carrier, rate type, country and contract, so treat these as useful starting points and verify the current rule before buying a label.

Example use	Imperial divisor	Metric divisor	Important note
FedEx U.S. packages	139 in³/lb	5,000 cm³/kg	Published common factor; service and location rules apply.
UPS U.S. Daily Rates	139 in³/lb	Confirm locally	UPS publishes a different U.S. Retail Rate factor.
UPS U.S. Retail Rates	166 in³/lb	Confirm locally	Use your rate type and current UPS guidance.
USPS applicable parcels	166 in³/lb	Not typically used	DIM rules include eligibility and cubic-size conditions.

How to reduce dimensional weight

Right-size the carton

Choose the smallest box that safely fits the item and required protective material.

Remove unused space

Repack awkward voids and avoid oversized cartons that carry mostly air.

Measure after packing

Use the finished outside dimensions; bowed sides can increase the measured cube.

Dimensional weight calculator FAQ

What is dimensional weight?

Dimensional weight translates package volume into a theoretical weight for shipping-rate purposes. It helps carriers price a large, light parcel according to the space it takes in a truck or aircraft.

How is shipping box dimensional weight calculated?

Multiply the box's outside length, width and height, then divide by the applicable DIM factor. For example, a 16 × 12 × 10 inch box divided by 139 has a DIM weight of 13.81 lb, commonly rounded up to 14 lb.

Should I round package dimensions?

Follow the carrier's current measurement rule. Many services require dimensions to be rounded to whole units before multiplying and the resulting weight to be rounded up. The calculator lets you turn dimension rounding off for an unrounded estimate.

What DIM divisor should I use?

Use the factor specified for your carrier, service, origin, destination and account. The presets cover common examples, while the custom option lets you enter a contract-specific divisor.

Is billable weight always the larger number?

Carriers commonly rate a parcel using the greater of actual weight and dimensional weight. Other rules—including minimums, cubic thresholds, oversize handling and surcharges—may also affect the final charge.

Does this online dimensional weight calculator save my data?

No account or upload is required. The calculation runs in your browser and your package measurements are not saved by this tool.