What is volumetric weight in simple words?

You have probably seen the phrase in a shipping dashboard and moved on. Volumetric weight is easier to grasp with a picture than with a formula, so here is the idea without the numbers.

Think of a courier van as a cupboard

A courier van, a train compartment or a plane hold has two limits. It can only carry so much weight, and it can only fit so much stuff. Now imagine two parcels.

• A small, dense parcel, such as a jar of pickle. It is heavy but takes little room.
• A big, soft parcel, such as a large box with one scarf and lots of air. It is light but takes up lots of room.

If the courier charged only by weight, the second parcel would be nearly free to carry, even though it fills a big part of the cupboard. That space could have carried several smaller parcels. So carriers think about space as well as weight.

What volumetric weight actually means

Volumetric weight is a stand-in figure. It answers the question, "if this box were filled with something dense, how heavy would it be?" It turns the size of your box into a weight-like number so that size and weight can be compared on the same scale.

The carrier then looks at two numbers, the real weight on the scale and the size-based figure. A common approach is to bill using the higher of the two. I cannot tell you what your courier's exact method is, so check their terms or your shipping dashboard to see how it works for you.

Who it affects most

You are likely to run into it if you sell:

• Soft goods in oversized boxes, like pillows, cushions or garments.
• Hollow items, such as baskets, hats or frames.
• Lightweight products in big gift boxes.
• Anything packed with lots of filler.

Dense products, such as jars, books or metal items, are usually charged closer to their real weight.

What it means for you in practice

• A bigger box is not free. It can raise your charge even when the product inside is tiny.
• Extra filler adds size, and size is what is being measured.
• A tighter box that still protects the product can bring the figure down.

That is why seemingly small decisions, like switching from a large box to a snug mailer, can change your bill.

What you can do today

Take your three best-selling products and look at the boxes you use. Ask whether each box is larger than it needs to be. If you can safely switch to a closer fit, do it. For a step-by-step calculation, see our volumetric weight worked example, which walks through the arithmetic.

Do not trade safety for size

Cutting the box too tight can cost more in breakage than you save in freight. Keep the cushioning that your product needs, and use how to write a product weight and dimensions section to record the packed measurements properly in your catalogue.

One last tip

Whenever you add a new product, measure the packed parcel and note down both the weight and the box size. That small record will save you from nasty surprises in your first shipping bill. For the bigger shipping picture, shipping across India, what small brands should know covers what else to watch.