Shipping & packaging
What Is a DIM Divisor?
A DIM divisor is the number carriers divide a package’s volume by to get its dimensional weight. It looks like a plain number, but it is really a ratio of volume to weight — which is why the same package can have very different dimensional weights depending on the divisor and the units it’s stated in.
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Volume per unit of weight
A divisor of 139 means 139 cubic inches count as one pound. A divisor of 5,000 means 5,000 cubic centimeters count as one kilogram. Dimensional weight = length × width × height ÷ divisor.
An 18 × 14 × 10 in box is 2,520 in³; at 139 that is 18.13 lb.
A divisor is a density in disguise
Turned around, a divisor says what density the carrier treats every package as having, at minimum. 1,728 in³ in a cubic foot ÷ 139 is about 12.43 lb per cubic foot; at 166 it is about 10.41 lb per cubic foot. In metric, 5,000 cm³/kg is 200 kg per cubic meter and 6,000 is about 166.67 kg/m³.
A package less dense than that bills on its size; a denser one bills on its scale weight.
| Divisor | Treated density |
|---|---|
| 139 in³/lb | ≈ 12.43 lb/ft³ |
| 166 in³/lb | ≈ 10.41 lb/ft³ |
| 5,000 cm³/kg | 200 kg/m³ |
| 6,000 cm³/kg | ≈ 166.67 kg/m³ |
Bigger divisor, lower weight
Dividing by more gives less. The 2,520 in³ box is 18.13 lb at 139 but 15.18 lb at 166 — 19 lb versus 16 lb when rounded up to whole pounds. That is why a divisor change can matter as much as a box change.
Where divisors come from
- Carriers publish divisors for their services, and they can differ between services and change over time.
- Contracts and negotiated rates may use their own divisor.
- Some services don’t use dimensional weight for every package. Always use the current figure for the service you ship with.
What Is a DIM Divisor FAQ
- What does a DIM divisor of 139 mean?
- That every 139 cubic inches of package count as one pound of dimensional weight.
- Why do divisors have units?
- Because a divisor is a volume per weight. 139 only makes sense with inches and pounds; with centimeters and kilograms the equivalent is about 5,022.
- Does a higher divisor mean lower dimensional weight?
- Yes. Dividing the same volume by a bigger number gives a smaller weight.
- Which DIM divisor should I use?
- The one your carrier currently states for the service and account you ship with. Examples such as 139 or 5,000 are only for illustration.
- Is a DIM divisor the same as a density?
- It is the inverse of one: 139 in³/lb corresponds to about 12.43 lb per cubic foot.
Related guides
- DIM Divisors ComparedHow the common DIM divisors 139 and 166 in³/lb and 5,000 and 6,000 cm³/kg compare, how to convert between them, and one box worked out with each.
- DIM Rounding ExplainedHow rounding dimensions and weights up changes dimensional and billable weight, with worked inch and centimeter examples and what to check with a carrier.
Open the tool
Jump into Custom DIM Divisor Calculator when you are ready to process your files.
