DIM weight describes package size as a weight
Dimensional weight converts the outside volume of a package into a weight value using a divisor. It exists because a large, light carton can consume substantial transport space even when its physical mass is low.
Packmetry keeps that calculation separate from packing geometry. Items are still placed using the carton’s internal dimensions. DIM analysis uses the carton’sexternal dimensions.
Packmetry does not assume a universal DIM divisor. Enter the divisor and units required by the carrier or workflow you are actually evaluating.
Why external dimensions are required
Dimensional weight describes the space occupied by the package from the outside. Falling back to internal dimensions would make the value look precise while measuring the wrong geometry.
For that reason, if DIM analysis is enabled, Packmetry expects external length, width and height for the cartons involved in that analysis.
Actual weight and DIM weight are different signals
Physical gross weight comes from the packed contents plus carton tare when those values are known. DIM weight comes from external package volume and the configured divisor. Neither value should silently stand in for the other.
When both are known, Packmetry can show an estimated chargeable weight as the greater of actual gross weight and DIM weight. That is intentionally described as an estimate rather than a shipping quote.
Packmetry is not a carrier-rate engine
Core DIM calculations do not apply carrier-specific billing rounding, service-level pricing, zone tables, surcharges or live rates. Those rules vary by carrier, service and contract and belong to a different layer of the product.
This boundary is useful: you can compare packing plans on dimensional-weight behavior without pretending that the result is a final shipping price.
When “Lowest DIM weight” is useful
The Business workspace can rank verified candidates by total dimensional weight when the required DIM settings and external carton dimensions are available. This can surface a different recommendation than simply choosing the fewest cartons or the least empty internal volume.
The important part is that the objective ranks verified packing candidates; it does not change the underlying physical fit rules.