Volumetric Weight Calculator

About this calculator

Couriers charge on whichever is greater: what the parcel weighs, or what it would weigh if it were dense. A large box of phone cases weighs almost nothing on the scales and costs as much to ship as a box of books, because it occupies the same space in the van.

Volumetric weight converts the box's size into a weight using a divisor set by the courier. Enter your dimensions and this calculator gives both figures, and the one you will be billed on.

How to use this calculator

1. Measure the outside of the packed box, not the product. Include the packaging.
2. Enter the three dimensions and say whether they are centimetres or inches.
3. Choose the divisor from your courier's rate card. Most Indian domestic services use 5000.
4. Add the actual weight if you have it, to see which figure you will be charged on.

The formula

Volume            = Length x Width x Height        (centimetres)
Volumetric weight = Volume / Divisor               (kilograms)
Chargeable weight = greater of volumetric and actual

The divisor represents the density the courier assumes. A divisor of 5000 means 5,000 cubic centimetres is treated as one kilogram. A smaller divisor produces a larger billed weight, so a service quoting 4000 is more expensive for the same box than one quoting 5000 — before you compare the per-kilogram rates at all.

Inches are converted at 2.54 cm per inch before the volume is calculated, so a box measured in inches gives the same answer as the same box measured in centimetres.

Worked example

A 30 × 20 × 15 cm box, actual weight 1.2 kg, on a courier using 5000:

Volume     = 30 x 20 x 15     = 9,000 cm³
Volumetric = 9,000 / 5000     = 1.8 kg
Chargeable = max(1.8, 1.2)    = 1.8 kg

You are billed on 1.8 kg, not 1.2 kg. The same box on a 4000 divisor would be 2.25 kg.

Notes and limits

• Measure the packed box at its widest points. Bulges and tape count.
• Couriers normally round the chargeable weight up to the next 500 g slab, which is why a 1.8 kg parcel is usually billed as 2 kg.
• Divisors vary by service, not just by company. Check the rate card for the specific service rather than assuming.
• Reducing box size is often the cheapest saving available. Dropping a 30 × 20 × 15 box to 25 × 18 × 12 cuts the volumetric weight by 40%.

What this calculation assumes

• Dimensions are of the packed box, including packaging.
• The divisor entered matches the specific service being used.
• Slab rounding is to the next 500 g, which is the common Indian practice.