5000 vs 6000: how the divisor changes the bill
The divisor is how many cubic centimetres of box count as one kilogram. A smaller divisor makes the same carton heavier: under 5000 a box is billed on volume sooner than under 6000.
- 5000 cm³/kg
- 200 kg/m³, about 139 in³/lb: DHL Express, Canada Post Priority and Xpresspost, US parcel carriers in inches
- 6000 cm³/kg
- 166.7 kg/m³, about 166 in³/lb: Canada Post Regular Parcel, UPS Retail Rates in inches, common in air cargo
- Difference
- The same carton’s volumetric weight is 20% higher under 5000 than under 6000
- Who sets it
- The service and your contract, not the shipper
What the two numbers mean
| Divisor | Same as | Billed on volume below | Published for, among others |
|---|---|---|---|
| 5000 cm³/kg | 138.4 in³/lb (139 in use) | 200 kg/m³ | DHL Express (DHL Express UK Service & Rate Guide 2026); Canada Post Priority, Xpresspost, Expedited, U.S. and international (Canada Post: how to cube an item) |
| 6000 cm³/kg | 166.1 in³/lb (166 in use) | 166.7 kg/m³ | Canada Post Regular Parcel (Canada Post: how to cube an item); common in air cargo |
US carriers state their divisors in inches and pounds: 139 for UPS Daily Rates, FedEx and USPS (from 12 July 2026), and 166 for UPS Retail Rates. 139 and 166 are the rounded inch equivalents of 5000 and 6000.
The same shipment under both
| Carton | Size (cm) | Scale (kg) | ÷ 5000: volumetric → billed | ÷ 6000: volumetric → billed |
|---|---|---|---|---|
| Box A · mugs | 40 × 30 × 25 | 4 | 6 → 6 | 5 → 5 |
| Box B · cushions | 60 × 40 × 30 | 8 | 14.4 → 14.5 | 12 → 12 |
| Box C · books | 30 × 25 × 20 | 9.5 | 3 → 9.5 | 2.5 → 9.5 |
| Shipment (with quantities) | 37.5 | 56.5 kg | 48.5 kg |
Quantities are 3, 2 and 1. Moving from 6000 to 5000 adds 8 kg (16.5%) to this shipment, all of it on the two light carton types. The dense book box bills its scale weight under both.
Open it in the calculator: the divisor comparison is under the totals
The cartons that flip
A carton between 166.7 and 200 kg per cubic metre is billed on volume under 5000 but on its scale weight under 6000. For example, 50 × 40 × 30 cm at 11 kg: 12 kg volumetric under 5000, billed 12 kg; 10 kg under 6000, so its 11 kg scale weight is billed.
You do not choose the divisor
The service and your account set it. Express parcel services commonly use 5000 (139 in inches); some economy and freight services use 6000 (166), and negotiated contracts can use either or another number. Picking the divisor that gives the lower number does not change what you will be invoiced. Use the one in your rate guide, and use the comparison only to see how much a different contract would matter.
Related
Last updated: 28 October 2026. Billable weight only: surcharges, minimum charges and your negotiated rates are not included.