How it is calculated
Carriers convert volume into weight with a divisor (or factor) from their price terms. For parcels the formula is usually:
Dimensional weight (kg) = length × width × height (cm) ÷ divisor
Example (with a divisor of 5,000 – check your own carrier's figure):
| Small box | Oversized box for the same product | |
|---|---|---|
| Dimensions | 30 × 20 × 15 cm | 50 × 40 × 30 cm |
| Volume | 9,000 cm³ | 60,000 cm³ |
| Dimensional weight | 1.8 kg | 12 kg |
| Actual weight | 2 kg | 2.3 kg |
| Chargeable weight | 2 kg (actual) | 12 kg (dimensional) |
The same 2 kg product can cost several weight classes more to ship if it is packed in a box that is too large.
Why it matters for ecommerce
- Light, bulky products (textiles, lamps, cushions, plastic goods) are often charged on dimensional weight.
- Excess void fill costs twice: the material and the extra freight.
- Accurate product dimensions are needed to choose the right box and shipping service automatically.
How to reduce dimensional weight
- Right-size the packaging – keep a range of box sizes that match your most common order profiles.
- Use bags or padded envelopes for soft goods that do not need a rigid box.
- Measure every SKU – store weight and dimensions in the item register so packing stations can pick the right box.
- Review per order profile – analyse which order combinations end up in oversized boxes.
- Compare services – some carriers or services use different divisors or size limits.
Right-sized packaging is also better for the environment. Our environmental policy commits us to fit-for-purpose packaging to avoid transporting air. See also order picking and packing.
Frequently asked questions
Which divisor should I use?
The one in your carrier's terms. Divisors differ between carriers, services and transport modes, so always calculate with the factor in your own agreement.
Does dimensional weight apply to pallets too?
Freight carriers usually apply their own volume or loading-metre rules to pallets and larger shipments. The principle is the same: space on the vehicle costs money.
How can a 3PL help reduce dimensional weight?
By choosing box sizes that fit the products, using appropriate packaging and keeping accurate dimensions for each SKU so the right box and shipping service can be chosen.
Short definitions in the glossary: Dims – dimensions · DIM weight – dimensional weight · Actual weight
This page gives general information about logistics terms. It is not legal, customs or tax advice, and it does not describe the terms of any specific agreement with Karlholm Logistics.