Which weight will the route actually charge — actual or volumetric?
The route charges the greater of actual weight, volumetric weight and any minimum billable weight.
Parameters last checked · defaults are templates, not quotes.
A parcel is billed on space as well as mass. Once a carton is bulky, the volume it occupies becomes the number that decides the postage, and adding a light item can raise the charge without adding meaningful weight.
This page compares both figures side by side for a single parcel type multiplied by a parcel count, so you can see which one is driving the invoice before you commit to a line.
"Volume exceeds mass by" reads like a penalty line, and it is not one: it is the distance between two candidate figures, taken before any route minimum is applied. Where the driver row names the minimum, neither the actual nor the volumetric total decides the invoice, and that gap can sit there without costing anything. Read the driver line first, then the two totals; if the minimum is the winner, the number that matters is the minimum itself, entered by hand and flagged not verified on this page.
A second misreading concerns the parcel count. Multiplying one carton’s volume by the number of parcels describes a shipment of identical boxes; a mixed load has to be run in parts and the totals added, because the tool rounds once, at the end of the multiplication, while carriers commonly round each parcel up. Multiply the displayed per-parcel figure by the count and compare it with the total row to see that effect. Above one parcel, treat the result as a lower bound on what a carrier will bill.
Chargeable weight comparison
Parcel
Common carrier divisors; use the one printed on your route.
Leave at 0 if the route publishes no minimum.
Chargeable weight
Chargeable weight
4,000 g
Volumetric weight decides the charge.
| Volume per parcel | 24,000 cm³ |
|---|---|
| Volumetric weight per parcel | 4,000 g |
| Total volumetric weight | 4,000 g |
| Total actual weight | 1,200 g |
| Volume exceeds mass by | 2,800 g |
Divisor 6000 g/L · not verified — final figures come from the carrier’s own weighing and rounding.
How to read the result
- The driver line tells you which figure won: actual weight, volumetric weight or the route minimum.
- A small divisor produces a bigger volumetric weight — 5000 g/L is less forgiving than 6000 g/L.
- Rounding happens per parcel on most routes, so several small boxes can bill higher than one larger box of the same total volume.
- This is an estimate: carriers weigh, round and apply minimums with their own rules.
- With more than one parcel the tool rounds the total once, whereas carriers usually round each parcel, so read the multi-parcel figure as a lower bound and check the rounding rule separately.
Formula, source and caveat
volumetric weight (g) = length × width × height (cm³) ÷ divisor (g/L) × 1000
- Source
- Published carrier practice; common divisors are 5000 and 6000 g/L.
- Caveat
- Some routes round per half kilogram instead of per gram.
chargeable weight = max(actual weight, volumetric weight, minimum billable weight)
- Source
- Same published practice.
- Caveat
- A route minimum can override both figures on light parcels.
Questions this tool raises
- Why is my volumetric weight larger than the product dimensions suggest?
- Packing adds air. A hoodie in a poly bag compresses; the same hoodie in a carton with corner guards does not.
- Does the divisor change per route?
- It can. Check the divisor printed on the line you intend to use and enter it here rather than trusting the default.
- Can I reduce volumetric weight without losing protection?
- Sometimes: removing a shoebox or asking for film instead of a carton lowers volume, at the cost of protection. See the merge and packaging notes.