Shipping Boxes: How to Choose the Right Cardboard Box for Shipping

The best shipping box isn't simply one your product fits inside.

It needs to be the right size, the right strength and the right style for what you're sending.

Choose a box that's too large and you may end up using unnecessary void fill, taking up more storage space and giving the product more room to move.

Choose one that's too small and you may not have enough space to protect the contents properly.

Then there's cardboard strength, box style, product weight and the journey itself to consider.

So whether you're shipping ecommerce orders every day or sending an occasional specialist product, here's how to choose the right cardboard shipping box.

What Is a Shipping Box?

A shipping box is simply a cardboard box suitable for protecting a product while it's being transported.

That could mean a parcel travelling:

• Through a courier network

• Through Royal Mail

• Between warehouses

• From a manufacturer to a retailer

• Directly to an ecommerce customer

• Within the UK

• Internationally

There's no single box style called a "shipping box".

A shipping box could be a conventional FEFCO 0201 cardboard box, a postal box, an overlapping-flap carton, a wrap-style box or a specialist box designed around a particular product.

Shipping describes what you're doing with the box – not necessarily the design of the box.

What Size Shipping Box Do I Need?

Start with the product.

Measure its maximum:

Length × Width × Depth

Then consider the protection it needs.

For example, does it require:

• Paper cushioning

• Protective wrapping

• Cardboard inserts

• Corner protection

• Dividers

• A second inner box

The internal dimensions of your shipping box need to accommodate both the product and the protection it genuinely requires.

But don't automatically add large amounts of extra space.

If your packed product needs approximately:

300 × 200 × 120mm

you probably don't want to put it into a:

450 × 350 × 250mm box

simply because that's the nearest box you happen to have.

The product fits.

But you're now shipping a considerable amount of empty space.

Right-Sized Doesn't Mean Tight-Sized

There's an important distinction here.

We talk a lot about right-sized packaging at ASC Direct.

That doesn't mean squeezing a product into the smallest possible cardboard box.

A fragile item may need plenty of space around it for appropriate cushioning.

A robust product may need very little.

So the objective isn't:

Smallest possible box.

It's:

Smallest appropriate box.

There should be sufficient room to protect the product properly without creating unnecessary empty space.

Why Does Shipping Box Size Matter?

Box size affects more than the appearance of the parcel.

Void fill

An oversized box may require additional paper, cushioning or other materials simply to stop the product moving.

Product movement

If the product has lots of empty space around it, it can move during handling unless it's properly secured.

Storage

Before you use a cardboard box, you have to store it.

Larger boxes take up more warehouse, stockroom or packing-area space even when supplied flat.

Packing time

A box that fits the product consistently can make it easier to develop a repeatable packing process.

Parcel dimensions

Some delivery services use size limits or dimensional criteria, so the external dimensions of the finished parcel can matter.

Don't spend your money filling fresh air.

Use the space the product actually needs.

Internal vs External Shipping Box Dimensions

This is particularly important when buying shipping boxes.

Internal dimensions tell you how much usable space is available inside the box.

External dimensions tell you approximately how large the finished parcel is on the outside.

They aren't the same.

Corrugated cardboard has thickness, so the external dimensions will be larger.

ASC Direct's Box Builder uses internal dimensions.

That makes sense when designing packaging around a product because you're specifying the space available inside the box.

But courier restrictions normally apply to the finished parcel.

So if you're trying to stay below a particular courier dimension, don't simply enter that maximum as the internal Box Builder size.

Allow for the cardboard thickness and finished construction.

What Type of Cardboard Box Is Best for Shipping?

There's no universal answer.

The most suitable style depends on what you're sending.

FEFCO 0201 Shipping Boxes

The FEFCO 0201 is the familiar cardboard shipping carton with flaps at the top and bottom.

It's one of the most versatile box styles available and works for an enormous range of products.

For many businesses, it's the logical starting point.

Postal Boxes

Die-cut postal boxes can be useful for smaller ecommerce products where quick assembly and presentation are important.

They're particularly common for clothing, cosmetics, gifts, accessories and other smaller retail products.

FEFCO 0203 Boxes

A 0203 has fully overlapping outer flaps rather than flaps that simply meet in the middle.

That additional overlap can provide reinforcement for certain applications.

Wrap Boxes

Wrap-style boxes can work particularly well for books, frames and flatter products because the cardboard wraps around the item rather than requiring it to be lowered into a conventional carton.

Long Shipping Boxes

Long products create different packaging challenges.

Guitars, golf clubs, hockey sticks, umbrellas, sporting equipment and long components can put considerably more stress on a box than a compact product.

For these applications, the box style, orientation and board strength become particularly important.

Single Wall or Double Wall Shipping Boxes?

One of the most common questions when choosing a shipping box is:

Do I need Single Wall or Double Wall cardboard?

The answer depends on more than weight.

At ASC Direct, our Single Wall board is approximately 3mm B flute.

Our Double Wall and Heavy Duty options are approximately 6mm, with Heavy Duty using a stronger board specification for more demanding applications.

As a general guide, ASC recommends no more than approximately 15kg for Single Wall, 20kg for Double Wall and 25kg for Heavy Duty, but these aren't guarantees that any box of that grade is automatically suitable for an item of that weight.

Product shape, dimensions, internal packaging and transit conditions also need to be considered.

A large, long and awkward 10kg product can place very different stresses on its box compared with a compact 10kg product.

Weight is one factor. Not the only factor.

When Is Single Wall Suitable?

Single Wall cardboard can be an excellent shipping option for:

• Smaller products

• Lightweight goods

• Compact ecommerce orders

• Robust products

• Shorter boxes

• Applications where excessive rigidity isn't required

There's little benefit in automatically specifying Double Wall for a product that can be adequately protected using Single Wall.

You're simply adding material and cost.

When Should I Consider Double Wall?

Double Wall becomes worth considering when:

• Products are heavier

• Boxes are larger

• Products are long

• Greater rigidity is required

• Contents are more vulnerable

• Parcels face more demanding handling

• Boxes may be stacked

But again, don't choose it purely because Double Wall sounds better.

Choose it because the application justifies it.

What About Heavy Duty Shipping Boxes?

Some products and journeys need something more substantial.

Heavy Duty cardboard boxes can be useful for demanding applications involving heavier products or situations where greater board strength is required.

But Heavy Duty shouldn't be the default for everything.

A correctly sized box using an appropriate board grade is normally preferable to simply putting every product into the strongest cardboard available.

Right size and right strength should work together.

Small Shipping Boxes

Small shipping boxes are useful for products such as:

• Components

• Cosmetics

• Accessories

• Electronics

• Collectables

• Gifts

• Ecommerce products

• Spare parts

With smaller products, it's particularly easy to grab a much larger stock box because it's convenient.

If that happens occasionally, it probably isn't significant.

If you're shipping hundreds of the same product, all that unnecessary space starts to add up.

Look for a smaller stock box first.

If an appropriate stock size isn't available, compare the cost of a custom-sized alternative.

Large Shipping Boxes

Large boxes require more thought.

As dimensions increase, so do the unsupported areas of cardboard.

That means you need to think about:

Rigidity

Board grade

Product weight

Weight distribution

Box style

Handling

Internal support

A large box doesn't automatically need to be Heavy Duty.

But you shouldn't choose the board specification based purely on weight either.

Large lightweight products can still create packaging challenges because of their dimensions.

Long Shipping Boxes

Long products deserve particular attention.

As a box becomes longer and narrower, it's more susceptible to bending and flexing.

ASC Direct stocks specialist long shipping boxes for products including guitars, golf bags, skis, hockey sticks, umbrellas, musical instruments and picture frames.

We can also manufacture long boxes to custom dimensions.

Depending on the product, a conventional FEFCO 0201 may not always be the best configuration.

A 0201 ALT end-opening box or another style can sometimes make more sense.

If you're sending an unusually long product, read our guide to choosing the right box for long items before ordering.

Shipping Boxes for Guitars & Musical Instruments

Musical instruments are a good example of why searching purely by box dimensions isn't always enough.

A guitar is:

Long.

Relatively narrow.

Potentially valuable.

And vulnerable to movement and impact.

ASC Direct stocks shipping boxes for acoustic and electric guitars as well as violins, saxophones, trumpets and other instruments.

But the outer box is only one part of the packaging.

The instrument still needs to be appropriately supported and protected inside it.

A specialist shipping box doesn't remove the need for appropriate internal protection.

How Much Empty Space Should Be Inside a Shipping Box?

There isn't a universal measurement such as:

"Always leave 20mm."

Different products need different levels of protection.

A robust product might need very little additional space.

A fragile item might need significantly more cushioning around every side.

Instead ask:

What protection does this product require?

Then size the box around:

Product + required protection.

That's a much better approach than choosing an oversized box first and filling whatever space happens to remain.

Should I Fill Empty Space in a Shipping Box?

If empty space allows your product to move around, it may need to be filled or otherwise restrained.

But if you're regularly using large quantities of void fill, consider why the empty space exists.

Perhaps the product genuinely needs cushioning.

Fine.

That's exactly what protective packaging is for.

But perhaps you're simply using a box considerably larger than necessary.

In that situation, the better solution may be a smaller box.

Use protective packaging because the product needs protection – not simply because the box is too big.

What Can I Use to Protect Products Inside Shipping Boxes?

The right protective material depends on the product.

Options can include:

• Paper cushioning

• HexcelWrap®

• Cardboard inserts

• Corrugated dividers

• Corner protection

• Tissue

• Other suitable protective packaging

Fragile products may need to be individually wrapped.

Multiple items may need separating so they can't collide during transit.

Whatever material you choose, the aim is to prevent damaging movement and protect vulnerable areas.

How Should I Seal a Shipping Box?

A conventional shipping carton such as a FEFCO 0201 will normally need packaging tape across its closing flaps.

Make sure the tape and sealing method are suitable for:

• The box

• Its weight

• The contents

• The journey

Heavier boxes may require a more substantial sealing method than lightweight parcels.

Some postal-style boxes use integral closures or self-seal strips, so always follow the intended closure method for the box you're using.

Can I Use Paper Packaging Tape?

For suitable parcels, paper packaging tape can provide an alternative to conventional plastic packaging tape.

It works particularly naturally alongside corrugated cardboard and paper-based protective packaging.

But, as with any packaging component, choose it according to the requirements of the parcel.

The objective isn't simply to remove plastic at any cost.

It's to create packaging that protects the product while avoiding unnecessary materials.

Can I Reuse a Cardboard Box for Shipping?

Potentially, yes.

But inspect it carefully first.

Check for:

• Crushing

• Tears

• Punctures

• Water damage

• Weak corners

• Damaged flaps

• Previous labels and barcodes

• Loss of structural rigidity

A cardboard box that performed perfectly on its first journey may have been weakened during handling.

If you're reusing one, make sure it's still appropriate for the contents and remove or cover old delivery labels that could cause confusion.

Shipping Boxes for Royal Mail

If you're sending through Royal Mail, choose packaging around the product first and then check the finished parcel against the requirements of the service you're using.

Don't automatically buy the largest box permitted by a Royal Mail parcel category.

The maximum size is a limit, not a target.

A smaller appropriately sized box may require less void fill and be easier to pack, store and handle.

Shipping Boxes for DPD

DPD advises that contents should be appropriately packaged for transport, with suitable outer packaging and internal protection.

If you're regularly sending the same product with DPD, choosing a consistent right-sized box can make the packing process more repeatable.

Read our full guide to choosing the right cardboard box for DPD parcels.

Shipping Boxes for Evri

Parcel dimensions can be particularly important when using different Evri services.

If a smaller appropriate shipping box allows a product to meet a particular service's size criteria, the packaging decision could potentially affect more than just the amount of cardboard and void fill you use.

Read our guide to choosing a right-sized box for Evri.

Shipping Boxes for FedEx

FedEx customers can use their own suitable packaging for many shipments.

For products better suited to a rigid cardboard carton than a mailing bag, choosing your own shipping box gives you the opportunity to match the packaging more closely to the product.

Read our guide to using your own cardboard boxes with FedEx.

What About International Shipping?

International parcels may travel much further and experience more handling than a typical domestic delivery.

That makes it particularly important to consider:

• Box condition

• Board strength

• Product movement

• Internal cushioning

• Sealing

• Moisture exposure

• Labelling

• Carrier restrictions

For fragile or particularly valuable products, additional protection or double-boxing may sometimes be appropriate.

Read our complete guide to safely packing items for international shipping for more information.

Stock Shipping Boxes vs Custom Shipping Boxes

There's nothing wrong with stock boxes.

In fact, if you can find a stock shipping box that fits your product properly and has the appropriate strength:

Buy it.

Mass-produced stock boxes can be extremely economical.

Custom packaging becomes interesting when you're repeatedly compromising.

Perhaps:

The nearest stock box is too large.

You're using lots of void fill.

You're cutting boxes down.

Your product has unusual dimensions.

Your current box is difficult to pack.

You're shipping the same product repeatedly.

Or you can't find the strength and dimensions you need in combination.

That's when it's worth comparing a custom-sized shipping box.

What Are Custom Shipping Boxes?

A custom shipping box is manufactured to dimensions selected around your product rather than being limited to predetermined stock sizes.

With the ASC Direct Box Builder, you can specify the internal:

Length × Width × Depth

and then choose your:

Box style

Board grade

Colour

Quantity

Printing options

and available production service.

You'll receive an instant online price based on that specification.

Custom-sized boxes start from just 25 boxes.

Are Custom Shipping Boxes More Expensive?

They can cost more per box than a mass-produced stock size.

That's why we wouldn't recommend custom packaging when a suitable inexpensive stock box already exists.

But compare the whole packing process, not just the empty box.

An oversized stock box might be cheaper to buy but require:

More void fill.

More storage.

More handling.

More packing time.

And potentially create a larger finished parcel.

The custom box might cost more.

The stock box might still be the better option.

Compare rather than assume.

Custom Shipping Boxes for Small Businesses

Custom packaging isn't only for businesses sending thousands of orders.

Low-volume manufacturing can be particularly useful for smaller businesses that:

Have limited storage.

Sell unusual products.

Want to test a new packaging size.

Have seasonal products.

Don't want to commit to hundreds of boxes.

Or repeatedly send one particular product.

ASC Direct's minimum Box Builder quantity is 25 boxes, making it possible to test a custom size without committing to a huge production run.

How Do I Choose the Best Shipping Box?

Before ordering, work through these questions:

1. What are the product dimensions?

Measure its maximum length, width and depth.

2. How fragile is it?

Determine what cushioning or protection it genuinely requires.

3. How heavy is it?

Weight helps determine the appropriate board specification, but don't consider weight in isolation.

4. Is it unusually long, flat or awkward?

A different FEFCO style may be more appropriate than a standard shipping carton.

5. How much empty space will be left?

Avoid unnecessary void space while retaining sufficient room for protection.

6. How will it be transported?

Consider the handling and requirements of your chosen carrier.

7. Does a stock box already fit?

If it does, compare it first.

8. Are you repeatedly shipping the same product?

If so, a made-to-measure box may be worth comparing.

Frequently Asked Questions About Shipping Boxes

What are the best boxes for shipping?

There isn't one best shipping box. The appropriate box depends on the product's dimensions, weight, shape, fragility and journey. Choose a box that's large enough for the product and its required protection without creating unnecessary empty space.

What cardboard boxes are best for shipping?

Corrugated cardboard boxes are widely used for shipping. Depending on the application, these can include Single Wall, Double Wall or Heavy Duty board and styles such as FEFCO 0201, 0203, postal boxes and wrap boxes.

Can I use any cardboard box for shipping?

A box should be in good condition and appropriate for the weight, dimensions and protection requirements of the contents. You should also check the packaging requirements of the carrier and service you're using.

Is Single Wall or Double Wall better for shipping?

Neither is automatically better. Single Wall can be appropriate for many smaller and lighter products, while larger, heavier, longer or more demanding products may benefit from Double Wall. The complete packaging application needs to be considered.

How much weight can a shipping box hold?

There's no universal weight capacity for all cardboard boxes. ASC Direct uses guideline maximums of approximately 15kg for Single Wall, 20kg for Double Wall and 25kg for Heavy Duty, but box dimensions, product shape, internal packaging and transit conditions also affect suitability.

Should a shipping box be bigger than the product?

Usually, yes, where space is required for cushioning or other protection. However, it shouldn't be unnecessarily oversized. Size the box around the product plus the protection it genuinely requires.

What are custom shipping boxes?

Custom shipping boxes are manufactured to dimensions chosen around a particular product rather than being limited to standard stock sizes.

What's the minimum order for custom shipping boxes?

ASC Direct's online Box Builder allows custom-sized cardboard boxes to be ordered from 25 boxes.

Are custom shipping boxes cheaper?

Not necessarily. A mass-produced stock box can have a lower unit price. Custom packaging becomes worth comparing when stock boxes are significantly oversized or create additional costs elsewhere in the packing process.

Can shipping boxes be printed?

Yes. Depending on the box specification and quantity, branding or other information can be printed onto corrugated shipping boxes.

Find the Right Shipping Box for Your Product

There are thousands of cardboard boxes available.

But you don't need thousands.

You need the one that suits your product.

Start with its dimensions.

Consider its weight and fragility.

Allow for the protection it genuinely requires.

Choose the appropriate cardboard strength and box style.

Then see whether a stock shipping box already meets those requirements.

If it does, use it.

If it doesn't, build the box around the product instead.

ASC Direct manufactures custom-sized cardboard shipping boxes from just 25 boxes, with instant online pricing through our Box Builder.

Right size. Right strength. Right box.

SHOP SHIPPING BOXES →

BUILD A CUSTOM SHIPPING BOX →

 

James Palfrey-Smith is the General Manager at ASC Direct with extensive experience in both operations and sales. James is passionate about solving packaging problems, delivering fast customer support, and building lasting relationships. Outside of work, he enjoys outdoor activities like hiking and skiing. A fan of real ale and business podcasts, he continuously seeks personal and professional growth. 

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