The price you pay is determined by the weight and destination. However, carriers often use “dimensional weight” instead of the actual weight.
Dimensional weight is also called “volumetric weight,” “DIM weight,” or “cubed weight.” It is an estimate of the package weight based on its dimensions and a minimum density. (That means the carrier has set a predetermined weight per cubic foot, regardless of the actual package weight.)
Carriers will charge their rate based on the larger of the two weights, dimensional or actual.
How is it calculated?
To determine actual weight, use a scale. Always round up (if necessary.)
To determine dimensional weight, use the following formula:
DIM Weight = (Length x Width x Height) ÷ Shipping Factor
Different carriers use different factors. The factor reflects the carrier’s minimum package density. The table below lists some common shipping factors.
| Carrier | Minimum Density | Shipping Factor |
| DHL | 12 lbs./ft.³ | 138 |
| FedEx | 12 lbs./ft.³ | 139 |
| UPS | 12 lbs./ft.³ | 139 |
| USPS | 10 lbs./ft.³ | 166 |
Example
Below is an example of a part that may seem like it was overcharged for shipping:
| Part | Actual Weight | Length | Width | Height |
| Part X | 5.5 lbs. | 74 in. | 11 in. | 7 in. |
DIM Weight = (74 x 11 x 7) ÷ 139 = 41 lbs.
In this example,
- UPS and FedEx will charge as if the package weighs 41 lbs.
- DHL would charge as if the package weighed 42 lbs.
- USPS would charge as if the package weighed 35 lbs.