Dimensional weight prices a parcel by the space it occupies. The billable weight is generally the greater of actual scale weight and applicable DIM weight.
DIM weight = length × width × height ÷ DIM divisorHow dimensional weight works
Parcel networks can run out of vehicle and aircraft space before they run out of payload. Dimensional weight, also called DIM or volumetric weight, converts a package's cubic size into a pricing weight. A large lightweight carton can therefore be billed as if it were much heavier.
Enter the finished outside dimensions of one package, its scale weight and the number of identical packages. FreightToolset compares the package's actual weight with the dimensional-weight result for the selected rule.
Current divisor notes for 2026
UPS publishes a divisor of 139 for Daily Rates and 166 for Retail Rates. FedEx U.S. guidance uses 139 for U.S., Puerto Rico and international parcel calculations. USPS changed the rectangular DIM divisor for listed domestic parcel services to 139 effective July 12, 2026, while retaining the one-cubic-foot applicability threshold described in the Domestic Mail Manual. DHL and many express networks commonly express the equivalent rule as 5,000 cm³/kg.
Carrier contracts, service levels and negotiated rates can differ, so treat presets as planning defaults and verify the rule on the rate sheet that governs your shipment.
How to reduce DIM weight
The only reliable way to reduce dimensional weight is to reduce the package's measured cube. Right-size the carton, remove unnecessary void fill, redesign protective inserts and avoid protrusions or bulges that increase the measured outside dimensions. A small reduction on each side can make a large difference because length, width and height are multiplied together.
Frequently asked questions
What is billable weight?
Billable weight is the pricing weight used for a shipment. For services using dimensional pricing, it is generally the greater of actual weight and applicable dimensional weight.
Why does UPS show both 139 and 166?
UPS publishes different DIM divisors by rate type: 139 for Daily Rates and 166 for Retail Rates. Your contract or service guide determines which applies.
Did USPS change its DIM divisor in 2026?
Yes. The current USPS Domestic Mail Manual for listed domestic parcel services shows a 139 divisor for rectangular parcels above one cubic foot, effective July 12, 2026.
Does this calculator quote shipping prices?
No. It calculates dimensional and billable weight only. Shipping prices also depend on origin, destination, service, surcharges and account terms.
Sources & verification
Verify carrier-sensitive rules against the source governing your shipment.
- UPS — Shipping Dimensions and Weight
- FedEx — General Packaging Guidelines
- USPS — Domestic Mail Manual 223
Formula reviewed September 29, 2026 Representative values and boundary cases are tested automatically.