Why Your Box Costs More Than It Should (And the Trick That Fixes It)

Somebody packs a big box because "better safe than sorry," half of it is empty air, and the quote comes back higher than they expected. Meanwhile a friend sent a smaller box, nearly the same weight, and paid less. Nobody explained why, so it just feels unfair.

It is not random. It is called volumetric weight, and once you understand it, you can pack smarter and pay less without changing a single thing about what you are sending.

The rule couriers actually use

Every courier charges you based on whichever number is higher: the actual weight on the scale, or the volumetric weight, which is a measure of how much space your box takes up. The formula is simple. Multiply the length, width, and height of your box in centimetres, then divide by 5000, the standard divisor most major couriers use. That gives you the volumetric weight in kilograms.

So a box that measures 60cm x 40cm x 30cm works out to 72,000 divided by 5000, which is 14.4kg of volumetric weight. If the actual contents only weigh 6kg, you are still charged for roughly 14kg, because the box, not the contents, is what is taking up the space.

Why this catches people out

It is not the heavy items that cause this problem. A box of palm oil, spices, or stockfish is usually dense enough that its actual weight matches or beats its volumetric weight, so you pay for what it really weighs. The problem is bulky, light items: clothes, plastic buckets, foam-packed electronics, anything with a lot of empty air trapped inside a bigger box than it needs.

The trick

Cut the box down to fit what is actually inside it. Not a bigger box "to be safe," the smallest sturdy box that the contents genuinely need. Less empty space means a lower volumetric weight, which means you are paying for your items, not for the air around them.

A few things that help in practice:

• Use the smallest box that still protects the contents. Resist the instinct to size up "just in case."
• Fill gaps with what you are already sending, like using clothing as padding instead of buying extra packing material that adds bulk.
• Pack dense items together and bulky items separately rather than mixing them, since mixing often forces you into a bigger box than either group needs on its own.
• If you are between two box sizes, do the maths first. A few centimetres can be the difference between paying for actual weight and paying for volumetric weight.

When it does not matter

If your box is full of heavy, dense items like garri, egusi, palm oil, or books, volumetric weight is unlikely to be your problem. This mostly affects shipments that are bulky relative to how much they weigh, so it is worth thinking about specifically when you are packing clothes, shoes, kitchen items, or anything with awkward shape.

Quick answers

Do I need to calculate volumetric weight myself before shipping? Not necessarily. If you are unsure, send us the dimensions and rough weight of your box on WhatsApp and we will tell you honestly whether you are better off with a smaller box.

What kinds of items are usually the worst for this? Clothing, shoes, plastic items, and anything foam-packed, since they take up more space than they weigh.

Can I get help picking the right box size before I pack? Yes. This is exactly the kind of thing to check before you seal anything, not after you get the quote.

Before you tape that box shut, send us a quick message with what is going in it. We will tell you the box size that saves you money, not just the one that feels safest.