Parcel and air
Dimensional Weight Calculator
This calculator converts package volume into dimensional weight and compares it with scale weight under the selected billing rule. DIM weight = rounded package length x width x height / divisor. Billable weight is the greater of actual and rule-rounded DIM weight. It follows a cited UPS and FedEx source record captured 2026-08-12.
Compare actual, raw DIM, rounded DIM, and billable weight with source-backed or custom rules.
Enter shipment details
Planning result
21.58 lb estimated billable shipment weight
- Raw DIM weight
- 21.583 lb each
- Rule-rounded DIM
- 21.58 lb each
- Actual weight
- 15 lb each
- Rule and divisor
- Custom divisor / 139
Custom mathematical workflow. Apply the exact divisor and rounding in your carrier terms.
Need quote requests too? Add this calculator to your logistics website and receive complete quote requests.
What this calculator returns
Use this dimensional weight calculator to compare package scale weight with DIM weight under UPS, FedEx, or a custom divisor. It is intended for parcel shippers, fulfillment teams, and rate analysts who need to see the raw calculation, carrier-style rounding, and estimated billable weight before buying a label or reviewing packaging.
How this is calculated
The calculator applies the selected rule to the package dimensions, multiplies length by width by height, and divides the resulting cubic inches by the dimensional divisor. The preset controls whether dimensions are rounded before multiplication and whether the resulting DIM weight is rounded up. The larger of actual weight and rule-rounded DIM weight becomes the estimated billable weight.
A divisor translates package volume into an equivalent weight. A lower divisor produces a higher dimensional weight for the same carton. Public carrier guidance can change by service and rate type, so the custom option lets a user apply the divisor and rounding written in a current agreement.
DIM weight = rounded package length x width x height / divisor. Billable weight is the greater of actual and rule-rounded DIM weight.
Variable definitions
- L, W, H
- Package length, width, and height in inches, subject to the selected dimension-rounding rule.
- Divisor
- The cubic-inch factor used to convert package volume into dimensional pounds.
- DIM
- Dimensional weight, calculated as L times W times H divided by the divisor.
- Billable weight
- The greater of actual scale weight and rounded dimensional weight, multiplied by package quantity.
Worked example
A carton measuring 20 by 15 by 10 inches has 3,000 cubic inches of volume. Using a divisor of 139, raw DIM weight is 3,000 divided by 139, or 21.58 pounds. If the selected rule rounds DIM weight up to the next whole pound, the rounded DIM weight is 22 pounds.
If actual scale weight is 15 pounds, the estimated billable weight is 22 pounds for one carton because DIM weight is larger. For three identical cartons, the displayed shipment estimate is 66 pounds, before any carrier minimums, special handling charges, or contract adjustments.
How to interpret the result
A DIM result above actual weight indicates that the package is relatively large for its weight. Reducing unused carton volume can lower the billable basis, but packaging must still protect the contents and meet the carrier service rules.
Always match the preset to the actual service and rate type. UPS public guidance distinguishes Daily Rates from Retail Rates, and account contracts can specify different terms. FedEx service guides and account terms also control the billed result.
What to measure
Use the outside packaged dimensions as the shipment will be tendered. Include pallets, skids, cartons, wrapping, overhang, and projections. Weigh the complete packaged unit, not only its contents. When pieces differ, create a separate row or calculation for each size and weight combination.
Assumptions and limitations
Divisors and rounding vary by service, rate type, lane, contract, and carrier. Custom divisor remains available for the terms on your quote.
- It does not calculate shipping price, zones, surcharges, minimum billable weights, or additional handling fees.
- It does not determine whether a package is accepted by a carrier or service.
- Preset rules reflect dated public guidance and may not match a negotiated account agreement.
- It assumes rectangular package dimensions and a separate actual weight for each identical piece.
Rules and sources used
Frequently asked questions
Why is DIM weight higher than actual weight?
Carriers use dimensional weight to account for the space a low-density package occupies. Large, light cartons can therefore be billed above scale weight.
What DIM divisor should I use?
Use the divisor in the current guide or contract for the exact carrier, service, origin, destination, and rate type. Use the custom setting when your agreement differs.
Are package dimensions rounded first?
That depends on the selected rule. Carrier guidance can require dimensions to be rounded before they are multiplied, which can change the final DIM weight.
Does this calculator include surcharges?
No. It estimates the billable weight basis only. Oversize, additional handling, residential, fuel, and other charges are separate.