Dimensional Weight Calculator
Compute a package's dimensional weight from its size and divisor, and see whether dim or actual weight gets billed.
Processed locally in your browser — nothing is uploaded.
Dimensional Weight Calculator
139 for major US carriers' retail rates; some accounts get 166.
Enter the package dimensions and actual weight.
About Dimensional Weight Calculator
Carriers bill the greater of a package's actual weight and its dimensional weight — volume divided by a divisor. Enter the box dimensions and actual weight, pick the divisor (139 in³/lb is standard for US domestic retail rates, 5000 cm³/kg internationally, both editable), and see the dim weight, which weight applies, and the billable result rounded up the way carriers round.
Common uses
- Predict shipping cost for a light, bulky box before printing a label
- Decide whether a smaller box drops you a billable-weight tier
- Compare domestic vs international billable weight for the same package
Example
Input
20 × 15 × 10 in, 10 lb actual, divisor 139
Output
Dim weight 22 lb → billed at 22 lb
Limitations
- Divisors and rounding rules vary by carrier, service, and negotiated account, and they change — the defaults are common published values, not a quote.
Frequently asked questions
What is dimensional weight in shipping?
A billing weight based on how much space a package occupies: length × width × height divided by the carrier's divisor. Carriers charge for whichever is greater — actual weight or dimensional weight — so a light but bulky box gets billed as if it were heavier.
What divisor should I use for dimensional weight?
139 in³/lb is the published divisor for major US carriers' domestic retail rates, and 5000 cm³/kg is the common international metric divisor. Some negotiated accounts get 166 in³/lb, which yields lower dim weights, so the field is editable.
Why is the dimensional weight rounded up to a whole number?
Carriers round dim weight up to the next whole pound or kilogram before comparing it to actual weight, and this calculator does the same. That's why a package computing to 21.1 lb bills as 22 lb.
Are my package dimensions shared with any carrier or server?
No. The calculation is done in your browser only — no dimensions, weights, or shipment details are transmitted anywhere, and nothing here creates a label or a quote.
How can I reduce dimensional weight charges?
Use the smallest box that safely fits the contents, since dim weight scales with all three dimensions — trimming 2 inches off each side of a 20 × 15 × 10 box cuts its cubic size by over a third. Charges only drop when the dim weight falls below your actual weight or crosses a billable tier.