Here's a real example: a customer ships a 0.4 kg silk scarf in a 30×30×30 cm box. The courier charges them for 5.4 kg. Why?
What is Volumetric Weight?
Volumetric weight (also called "dimensional weight" or "DIM weight") is a pricing technique used by all international couriers. It charges you based on whichever is higher: the actual weight of the package or the volume-based weight.
Why? Because airplane cargo space is limited. A lightweight but bulky package takes the same room as a heavy one — so the courier charges for the space, not just the mass.
The Formula
For international air freight, the standard formula is:
Volumetric Weight (kg) = (Length × Width × Height in cm) ÷ 5000
Example: A 30×30×30 cm box = 27,000 cm³ ÷ 5000 = 5.4 kg volumetric weight. Even if the actual scarf weighs 400g, you're billed for 5.4 kg.
Different Divisors by Courier
Not all couriers use 5000. Here are the common divisors:
- DHL, FedEx, UPS Express — 5000
- India Post EMS — 6000 (slightly more forgiving)
- Some economy services — 6000 to 8000
This is why a 30×30×30 box might cost ₹4,200 via DHL but ₹3,500 via India Post EMS for the same goods.
How to Calculate the Chargeable Weight
- Weigh the package (actual weight).
- Measure L × W × H in centimeters.
- Calculate volumetric weight = (L × W × H) ÷ 5000.
- Chargeable weight = max(actual weight, volumetric weight), rounded up to the next 0.5 kg.
4 Ways to Save Money
- Use smaller boxes — even 10% smaller dimensions saves 30% on volumetric weight
- Vacuum-pack soft items — clothes, scarves, plushies all compress dramatically
- Compare couriers — economy services use higher divisors
- Consolidate orders — one 2 kg box is cheaper than two 1 kg boxes (volumetric grows linearly, but minimum charges don't)
ShipReward's Volumetric Calculator
Every order page on ShipReward automatically calculates both actual and volumetric weight as you type the dimensions. You see your real chargeable weight before you even hit "Get Rates" — no surprises at billing. Try the order flow.
Bottom line: pack smart, and you'll cut shipping costs by 20-40% without changing couriers.