There is no single official list of shipping box sizes, but a small set of dimensions turns up again and again because they stack well on a pallet, fit standard corrugated sheet sizes, and suit the things people ship most. Below is a chart of those common sizes, what each one tends to hold, and how to pick the right one for what you sell.
The most common shipping box sizes are 6 x 6 x 6, 8 x 6 x 4, 10 x 8 x 6, 12 x 9 x 6, 12 x 12 x 12 and 18 x 18 x 18 inches, written length by width by height. For small items, 6 x 6 x 6 and 8 x 6 x 4 cover most orders. Pick the smallest size that fits the product plus its padding.
Common shipping box sizes
Sizes are written length by width by height in inches, measured across the opening. If that order is unfamiliar, start with how to measure a box.
| Size (LxWxH) | Band | Commonly holds |
|---|---|---|
| 6 x 6 x 6 | Extra small | Candles, mugs, small jars, single cosmetics |
| 8 x 6 x 4 | Small | Books, phone accessories, small electronics |
| 8 x 8 x 8 | Small cube | Bakery items, gift sets, homeware |
| 10 x 8 x 6 | Small to medium | Shoes, small apparel orders, subscription boxes |
| 12 x 9 x 6 | Medium | Multi item ecommerce orders, folded apparel |
| 12 x 12 x 12 | Medium cube | Kitchenware, bulkier single items |
| 14 x 14 x 14 | Large cube | Multi item orders, lightweight bulky goods |
| 16 x 12 x 12 | Large | Larger apparel runs, small appliances |
| 18 x 18 x 18 | Extra large | Bulk orders, retail outer cartons |
| 24 x 18 x 18 | Oversized | Wholesale cases and pallet building |
What are standard shipping box sizes?
Strictly speaking, there is no standard set by any authority. What people mean by standard is the sizes box plants keep tooling for, because those cut efficiently from a standard corrugated sheet and waste the least board. The chart above covers most of them. Anything outside that list is a custom size, which is normal and often cheaper overall once you count the void fill and shipping you stop paying for.
The same sizes in centimeters
One inch is exactly 2.54 centimeters, so the common sizes convert as below, rounded to one decimal place.
| Inches | Length cm | Width cm | Height cm |
|---|---|---|---|
| 6x6x6 | 15.2 | 15.2 | 15.2 |
| 8x6x4 | 20.3 | 15.2 | 10.2 |
| 8x8x8 | 20.3 | 20.3 | 20.3 |
| 10x8x6 | 25.4 | 20.3 | 15.2 |
| 12x9x6 | 30.5 | 22.9 | 15.2 |
| 12x12x12 | 30.5 | 30.5 | 30.5 |
| 14x14x14 | 35.6 | 35.6 | 35.6 |
| 16x12x12 | 40.6 | 30.5 | 30.5 |
| 18x18x18 | 45.7 | 45.7 | 45.7 |
| 24x18x18 | 61.0 | 45.7 | 45.7 |
How to choose the right shipping box size
- Measure the product, not the old box. Take the length, width and height of the item at its widest points, including any inner packaging.
- Add clearance, not room. A small amount of space on each side is enough for most goods. More than that and the product moves in transit.
- Account for protection. If you use bubble, foam or an insert, add its thickness to every dimension before you pick a size.
- Think about the box being closed. Flaps need to meet. A box packed to the brim will not seal flat and will not stack.
- Check it stacks. If you ship in volume, a size that palletises cleanly saves more than the box itself costs.
How box size affects what you pay to ship
Carriers do not price on weight alone. They compare the actual weight of your parcel against a figure worked out from its dimensions, and they charge on whichever is greater. That is dimensional weight, and it is why an oversized box full of air can cost more to send than a smaller one holding the same product.
The practical takeaway is simple. Every inch you remove from a box you did not need is money you stop paying on every single order, for as long as you sell that product. Carriers publish their current dimensional weight rules on their own sites, and those rules change, so check the live figures rather than relying on a number you read in an article.
How much weight each box size can carry
Size and strength are separate choices. Under the freight classification tables for corrugated boxes, a single wall 32 ECT box may carry up to 65 lb of box and contents, as long as its length, width and depth add up to no more than 75 inches. Every size in the chart above is inside that limit; even 24 x 18 x 18 adds up to 60 inches.
Heavier loads move up to 44 ECT board, rated for 95 lb, or to double wall. Treat those figures as ceilings, not targets, because humidity, handling and stacking time all reduce real strength. The corrugated board specifications reference has the full tables.
Carrier boxes versus your own boxes
Carriers supply their own boxes for certain services, and for occasional shipments they are a reasonable option. They are also unbranded, fixed in size, and tied to that carrier.
If you are shipping your own products regularly, your own box usually wins on three counts. It fits the product properly rather than approximately, it carries your brand instead of someone else’s, and it is not locked to one carrier. For current carrier box dimensions and any service restrictions, check the carrier directly, because those details are updated more often than most articles are.
When a custom size beats a standard one
A standard size is the right answer when your product happens to fit one. Plenty do. It becomes the wrong answer when you find yourself filling half the box with padding, or squeezing a product into something slightly too small because the next size up is too big.
At that point a custom size is worth pricing. There is no minimum order here, so you can build the exact dimensions your product needs and run a small batch to test it before you commit to a bigger quantity. Send the product dimensions and we will work the box around them. You can browse shipping boxes, white shipping boxes and custom corrugated boxes first, or send them through the quote form.
Shipping box size FAQs
What is the most common shipping box size?
There is no single winner, but 12 x 9 x 6 and 10 x 8 x 6 cover a very large share of everyday ecommerce orders. Cube sizes such as 8 x 8 x 8 and 12 x 12 x 12 are close behind because they suit awkward shaped goods.
Are box dimensions inside or outside measurements?
For corrugated boxes, dimensions are almost always internal, because what matters is what fits inside. The outside is slightly larger by the thickness of the board. It sounds like a small difference and it is exactly the difference that stops a product fitting.
Does a bigger box always cost more to ship?
Usually yes, because of dimensional weight. A larger box can be charged as though it were heavier than it is, even when the contents are light.
Can I get a shipping box in a size that is not on the chart?
Yes. Any dimension can be made to order, and with no minimum you can test a size before scaling it.
Related guides
Work through the sizing first with how to measure a box, then compare board types in the corrugated boxes guide. If you need the actual board strength numbers, the corrugated board specifications reference has the ECT and Mullen carrier tables. If you are shipping smaller retail orders, mailer boxes may suit you better than a shipping carton. When you are ready to order, see custom shipping boxes with no minimum order.
Frequently asked questions
What are common box sizes for small items?
For small items, 6 x 6 x 6 and 8 x 6 x 4 inches are the usual starting points. The first suits candles, mugs, small jars and single cosmetics, and the second suits books, phone accessories and small electronics. Choose the smallest size that fits the item plus its padding.
What size box do I need for my product?
Measure the product at its widest points, including any inner packaging, and add the thickness of any padding or insert to every dimension. Then pick the smallest box whose inside dimensions meet those numbers with only a little clearance, so the flaps still close flat.
How do I convert box sizes from inches to centimeters?
Multiply each dimension by 2.54, because one inch is exactly 2.54 centimeters. A 12 x 9 x 6 inch box is about 30.5 x 22.9 x 15.2 centimeters, and a 12 x 12 x 12 inch box is about 30.5 centimeters on each side.
Why does box size change the shipping price?
Carriers compare the actual weight of a parcel with a dimensional weight worked out from its size, and they charge whichever is greater. An oversized box full of air can cost more to ship than a smaller box holding the same product, so trimming unneeded inches saves money on every order.
