Field note5 min read
Dimensional Weight Explained: Actual vs. DIM Weight
Why a 12-pound carton can rate at 22 pounds, and which number to check before purchasing a label.
Three weights, one rating decision
Actual weight is what the scale reads. Dimensional weight converts package volume into a density-based weight. Billable weight is normally the greater applicable value after the carrier’s measurement and rounding rules.
FORMULA
Billable weight = max(Actual weight, L × W × H ÷ divisor)
The divisor is a density rule
For the same carton, a smaller divisor produces a larger DIM weight. Do not copy a divisor from another service: use the rate guide or contract tied to the shipment.
| Carton volume | Divisor | Unrounded DIM |
|---|---|---|
| 3,000 in³ | 139 | 21.58 lb |
| 3,000 in³ | 166 | 18.07 lb |
Packing-station checklist
- •Measure the sealed outside dimensions at the extreme points.
- •Select the correct rate type or service.
- •Apply the published dimension and weight rounding sequence.
- •Compare the result with scale weight.
- •Keep enough protection; right-sizing is not under-packing.