Topic reference · reviewed August 2026
Dimensional Weight: Formula, Divisors & Worked Examples
A practical reference for DIM weight, chargeable weight, carrier divisors, measurement rules, rounding, and multi-parcel examples.
Dimensional weight converts parcel volume into a billing weight. Multiply the finished outside length, width, and height, divide by the factor specified for the carrier service, then compare that result with actual packed weight. The larger value is normally the starting chargeable weight before the applicable rounding and eligibility rules are applied.
Core method
The formula
Worked example
Put numbers through it
A 20 × 16 × 12 inch parcel has 3,840 cubic inches. At a divisor of 139, dimensional weight is 27.63 lb. If actual packed weight is 24 lb and the service rounds chargeable weight up to whole pounds, the planning result is 28 lb per parcel.
Calculate your shipment
Dimensional Weight Calculator — FedEx, UPS, DHL & USPS
Calculate dimensional and chargeable weight with planning presets for FedEx, UPS, DHL, and USPS, or enter your own divisor and rounding rule for a contracted service.
Common questions
Answers you can verify.
Each answer states the planning rule and points to the longer working guide when the decision needs more context.
What is dimensional weight?
Dimensional weight is a calculated billing weight based on the outside volume of a parcel. It lets a carrier compare the space a parcel occupies with its actual scale weight.
Which dimensional-weight divisor should I use?
Use the divisor stated for the exact carrier, service, rate type, account, and destination. Public examples such as 139, 166, or 5,000 are useful presets but are not universal contract terms.
Read the worked guide ↗Is chargeable weight actual or dimensional weight?
It is commonly the larger of actual packed weight and dimensional weight, followed by the service's measurement and billing-rounding rules.
Should I round each parcel or the shipment total?
Follow the carrier's stated sequence. Many parcel calculations apply measurement and chargeable-weight rounding per package before multiplying the quantity.
Read the worked guide ↗How can packaging reduce dimensional-weight charges?
Measure finished parcels, rank high-volume SKUs by billed-weight gap, test smaller packs, and verify that freight savings exceed material, labour, and damage-risk changes.
Read the worked guide ↗Supporting guides
Go from formula to operating decision.
Compare common parcel DIM factors without treating a public rule as a substitute for your service contract.
7 minDimensional-weight rounding: worked parcel examples ↗See why measuring and rounding at the correct step can change billed weight across a multi-parcel shipment.
7 minA practical dimensional-weight packaging audit ↗Find cartons that are quietly increasing parcel charges, then test changes without weakening the pack.
Primary references
Public references are starting points. Your current contract, tariff, equipment specification, and operating procedure control the final decision.
FedEx dimensional weight guidance ↗UPS dimensional weight guidance ↗DHL volumetric weight guidance ↗