Two things decide what you are billed: the weight slab and the chargeable weight.
Weight slabs
Couriers do not bill per gram. They bill in steps, commonly 500g or 1kg. A 520g parcel on a 500g slab is billed as 1kg. Packaging that pushes you a few grams over a slab boundary is one of the most common silent costs in ecommerce.
Volumetric weight
A large, light parcel takes up space a heavy small one does not. Couriers charge for whichever is greater: actual weight, or volumetric weight.
The standard surface formula in India is:
volumetric weight (kg) = (length x width x height in cm) / 5000
A 30 x 25 x 20 cm box has a volumetric weight of 3kg, even if it weighs 900g. You will be billed 3kg.
How to cut the bill
- Right-size the box. Reducing each dimension by a couple of centimetres often drops a whole slab.
- Weigh with packaging on. Your billed weight includes the box, filler, and tape.
- Watch the slab boundary. Lighter filler can move a 1.05kg parcel back under 1kg.
- Reconcile every invoice. Weight discrepancy charges applied after pickup are common; dispute the ones that are wrong.
RoutikQ shows the chargeable weight and the slab used on every shipment, so there is no guesswork at invoice time.