01 · Calculator
Volume First.
Billable Weight Second.
DIM weight gets expensive when packaging wastes cube. This calculator lets a shipper test package dimensions quickly and see whether rating will happen off actual weight or off the space the shipment occupies.
Results
Billable weight estimate
This compares rounded actual weight against rounded DIM weight per package. The higher number becomes the billable weight.
Billable weight / pkg
17
lb charged per package
DIM weight / pkg
17
Raw calc 16.6 before rounding
Total billable
17
lb across 1 package
Actual weight
10
Rounded actual weight per package. Total actual weight is 10 lb.
Dimensional weight
17
Volume ÷ divisor, then rounded up. Total DIM weight is 17 lb.
Per-package volume
2,304 cubic inches
Divisor used
139 based on the selected preset or custom rule.
Charge basis
This shipment is currently billed by dimensional weight, because that value is higher after rounding.
Important note
Carrier contracts, service type, zone, and packaging rules can change the divisor or rounding behavior. Verify against your rate guide before rating a live shipment.
02 · Method
How the Math
Actually Works
Multiply package length by width by height, divide by the relevant divisor, then round up. Compare that number with rounded actual weight. The larger value becomes the billable weight.
Measure at the Longest Points
Length, width, and height should reflect the actual packaged dimensions, not the product alone. Oversized cartons drive DIM charges even when the item is light.
Apply the Divisor
The divisor converts package volume into a billable weight equivalent. A smaller divisor produces a higher DIM weight and therefore more charge exposure.
Bill the Higher Number
Carriers generally compare rounded actual and rounded dimensional weights per package. If DIM wins, you are paying for cube instead of mass.
03 · Presets
Common Divisors.
Still Verify the Contract.
The presets are meant to get you close fast. Final rating can still depend on your carrier, service level, zone, and negotiated pricing rules.
139
Common parcel divisor in inches and pounds. FedEx’s published DIM help content currently references `139` for U.S. pound-based DIM math.
166
Appears in UPS freight examples and certain lower-density freight calculations. Useful when your lane or service is not using parcel-style `139`.
5000 / 6000
Metric divisors for centimeter/kilogram workflows. Use these for international or metric rate guides, or enter a custom divisor for contract-specific rules.
Need Another
Shipping Tool?
The tools library is expanding around recurring freight and dock questions. If there's another calculation your team uses constantly, send it over.