Volumetric Weight Explained: How Your Shipping Cost Is Really Calculated

If you've ever been quoted a shipping price that seemed too high for a "light" parcel, volumetric weight is probably the reason. Here's how it actually works.

The formula

Most air couriers and freight forwarders calculate volumetric (dimensional) weight like this:

Volumetric weight (kg) = Length × Width × Height (cm) ÷ 5000

The divisor varies by carrier — 5000 is the most common for express, some channels use 6000. Always confirm with whoever ships your goods.

Chargeable weight = whichever is greater

Your bill is based on the chargeable weight: the greater of the actual weight and the volumetric weight. Example:

A box of phone cases: 40 × 30 × 30 cm, actual weight 3 kg
Volumetric weight = 40 × 30 × 30 ÷ 5000 = 7.2 kg
You pay for 7.2 kg, not 3 kg.

This surprises a lot of first-time buyers. Small, light, bulky items — plush toys, packaging-heavy goods, anything with a lot of air inside the box — almost always bill on volumetric weight.

How to keep it down

Ask the seller for the packed dimensions before you buy, not just the product size.
Avoid oversized outer boxes. Sellers often ship in whatever box is handy.
For multi-item orders, consolidation helps: repacking several small parcels into one well-packed box usually reduces total volumetric weight.

When I quote shipping for clients, I always calculate both weights and bill on the chargeable one — no surprises later. If you want a quick check on an order you're planning, send me the product link and box dimensions on WhatsApp and I'll run the numbers free.

Frequently asked questions

Does volumetric weight apply to sea freight too?

Less so. Sea freight is usually charged by volume (CBM) directly rather than a volumetric-weight formula, but the principle is the same: bulky goods cost more than their weight suggests.

Why is the divisor sometimes 5000 and sometimes 6000?

Each carrier sets its own divisor based on the aircraft and routes. Express couriers mostly use 5000; some economy air channels use 6000. Your forwarder should confirm which applies before quoting.