What the result means
Dimensional weight assigns a planning weight to the space a package occupies. Carriers may compare DIM weight with actual scale weight and use the greater figure when determining billable weight.
Choose the divisor carefully
The divisor is deliberately editable. There is no safe universal value for every carrier, service, country, or contract. Current FedEx U.S. guidance commonly uses 139 for U.S., Puerto Rico and international shipments. UPS Canada currently lists 139 for many services and 115 for certain domestic air services. Confirm the current carrier documentation for your shipment.
How to measure
- Measure the outside of the finished package.
- Use the carrier’s required rounding method.
- Include bulges or protrusions where applicable.
- Weigh the fully packed parcel, not the product alone.
Why right-sizing helps
Reducing unused box volume can lower calculated DIM weight and also reduce cardboard, cushioning and storage. Do not reduce protection below what the product needs.
Related calculations
Need a size check rather than a weight estimate? Use the length + girth calculator. For a box starting point, use the box size chooser.