Postage rates are calculated by the weight of the package and the dimensions. When postage is calculated based on dimensions this refers to dimensional weight. This is a common industry practice with shipping carriers like USPS, FedEx, Canada Post and UPS to name a few. Carriers will calculate postage based on the greater of the two: actual weight or dimensional weight.
What is dimensional weight?
Dimensional weight, also known as volumetric weight, is a standard for which carriers use to calculate postage. It is calculated from the length, width and height of a package. For example if you have a 5 lb package that is packaged in a larger box (i.e. 20″ x 20″ x 20″), this package will take up more space (volume) than if it was in a box with smaller dimensions (i.e. 5″ x 5″ x 5″). Therefore carriers will charge postage based on the dimensional weight versus the actual weight.
It is always important to be accurate with your weight and dimensions to ensure you pay accurate shipping costs.
- Avoid underestimating dimensions or weight. Most carriers will always round up weight to the next point. For example, USPS will calculate postage for 1.3 lbs at 2 lbs.
- Postage adjustments may be applied for inaccurate weight and dimensions.
- Shipments can be returned to sender or delivered to your customer with postage due if postage is inaccurately purchased for your package.
Your packaging matters! Package your item as small as possible to minimize extra packaging that could be factored when calculating shipping costs.