E-commerce boxes: how to save on shipping
Online shops send a lot of parcels, and every extra centimetre costs money. Here is how to choose boxes that cost less to ship.
Updated 16 October 2026
Couriers also look at volume
Many couriers charge not only for the weight of a parcel but also for the space it takes up: the volumetric weight. It is worked out like this:
length × width × height (in cm) ÷ a fixed number, often 4000 or 5000 depending on the courier.
The courier charges whichever is higher, the real weight or the volumetric weight. That is why a box that is too big costs more to ship, even if the product is light.
| Box (cm) | Volumetric weight (÷ 5000) |
|---|---|
| 40 × 30 × 30 | 7.2 kg |
| 35 × 25 × 20 | 3.5 kg |
Same 2 kg product, but with the smaller box you pay for about half the weight.
You will find the number to use in your courier's price list: ask for it before choosing your box sizes.
A made-to-measure box
A box of the right size leaves less empty space: less volume to pay for and less filler to buy, such as bubble wrap, paper or polystyrene. The product also moves less in transit, so fewer breakages.
We make plain kraft slotted boxes to measure from 50 pieces, so even a small shop can have its own size. Measure your product carefully with the guide How to measure a box.
The right board, not the thickest
More board means more weight. For light products single wall is often enough; for heavy or fragile products double wall is better. In Design your box you also see the estimated weight of the empty box. The differences are explained in Single or double wall?
Slotted or self-assembly?
The regular slotted box costs less and is ideal when shipping is what matters most. The self-assembly box closes without tape and looks good when your customer opens the parcel: it is your business card. We compare them in Slotted or self-assembly box?
A few sizes, well chosen
Look at what you ship most often and choose two or three sizes that cover most orders. With fewer sizes you order more of each, your stock is tidier and whoever packs the parcels makes fewer mistakes.
Need a box right away? Look at the ready-stock boxes on our website: collect them from us or we ship them to you.
Frequently asked questions
How is volumetric weight calculated?
Multiply length, width and height in centimetres and divide by the number your courier uses, often 4000 or 5000. You pay whichever is higher, the real or the volumetric weight.
What is the minimum order for a made-to-measure box?
Plain kraft slotted boxes in double wall are made from 50 pieces. With single wall, a logo, a colour or for self-assembly boxes the minimum is 100 pieces.
Do the boxes arrive assembled?
No, they arrive flat: they take up little room in storage and you fold them when you pack the parcel.
Found the box you need?
Draw it with your own dimensions in Design your box and get a quote, or tell us what you need to pack or ship.