Chargeable Weight Calculator

About this calculator

Chargeable weight is the number on the invoice. It is not what the parcel weighs and it is not its volumetric weight — it is whichever of the two the courier decides to bill, rounded up the way that courier rounds.

Both halves matter. A 1.6 kg parcel with a volumetric weight of 2.1 kg is billed at 2.5 kg once half-kilogram rounding is applied, which is 56% more weight than the scales showed.

How to use this calculator

1. Choose your courier if it is configured here, so its own rounding and divisor are used. Otherwise choose "enter a rate myself" and supply the divisor from your rate card.
2. Enter what the packed parcel weighs, in whichever unit your scale reads.
3. Enter the outside dimensions of the packed parcel.
4. Read the chargeable weight, with the comparison that produced it shown underneath.

The formula

Volumetric weight = (L x W x H) / Divisor
Chargeable weight = greater of actual and volumetric
Billed weight     = chargeable, rounded by the courier's rule

Most couriers take the greater of the two, but not all: some price small parcels on actual weight only, and some freight services bill on volume regardless. Where a courier is configured here, its own policy is applied rather than the usual one.

Rounding is the step people forget. A courier that bills in 500 g slabs turns 2.1 kg into 2.5 kg; one that bills in whole kilograms turns it into 3 kg. Rounding is always upwards.

Worked example

A parcel weighing 1.6 kg, measuring 35 × 25 × 12 cm, on a 5000 divisor:

Volume     = 35 x 25 x 12  = 10,500 cm³
Volumetric = 10,500 / 5000 = 2.1 kg
Chargeable = max(2.1, 1.6)  = 2.1 kg

Billed at 2.1 kg exactly where the courier bills to the gram, or 2.5 kg where it rounds to the next half kilogram.

Notes and limits

• Weigh and measure the parcel after packing. The courier measures what it receives.
• Rounding is applied after the comparison, never before it.
• Where no courier is chosen, no rounding is applied - the exact chargeable weight is shown, which is the floor of what you will be billed.
• If your invoice shows a heavier weight than this, the usual causes are a different divisor, a rounding rule you did not know about, or a parcel measured at its bulges rather than its nominal size.

What this calculation assumes

• Both the weight and the dimensions are of the parcel as handed over.
• Where no courier is selected, the usual "greater of the two" policy is applied with no rounding.
• Where a courier is selected, its configured policy, divisor and rounding are used instead.