Most businesses do not need a separate box for every product. They also should not force every order into one universal carton just to make packaging stock easier to manage.
When I assess box sizing, I look for the smallest practical set of sizes that handles the orders a business actually packs well.
That might be one box. It might be three. A business selling 30 products can sometimes operate with fewer shipping sizes than another selling five products with very different shapes, weights and protection needs.
My rule is simple: a new box size should earn its place.
It should solve a repeated problem in fit, protection, parcel volume, packing time or presentation strongly enough to justify another specification to order, store and manage.
One Box Size or Multiple Sizes? The Short Answer
Use one box size when your products or typical orders are similar enough in packed dimensions, weight and protection needs that the same carton works without excessive empty space.
Add another size when a meaningful share of orders repeatedly needs too much filler, allows excessive movement, creates unnecessary parcel volume, takes longer to pack or looks obviously oversized when opened.
The important word is repeatedly.
One awkward order every few weeks normally does not justify another custom carton. The same workaround happening hundreds of times is different.
I would rather manage three useful sizes that handle most orders properly than ten cartons created simply because ten products have different measurements.
Start With Orders, Not the Number of Products You Sell
One of the easiest ways to overcomplicate packaging is to start with the product list.
I prefer to start with what customers actually order together.
Imagine a skincare business selling cleanser, moisturiser, serum, toner, eye cream and several gift combinations.
Six products do not automatically mean six shipping boxes.
Actual orders might fall into three natural groups:
Those packing situations tell me much more than the number of products in the catalogue.
The same logic applies to clothing, candles, food products, electronics and subscription orders.
Product dimensions still matter. If those have not been confirmed properly, How to Measure a Box for Custom Packaging is the place to start before making structural decisions.
Measure the product as it will actually be packed, including its retail carton, insert, wrapping or protective components.
When One Box Size Is the Better Choice
Using one size is not automatically a compromise. Sometimes it is the better commercial decision.
Similar packed dimensions do not need artificial differences
Suppose an apparel business sells T-shirts in several sizes.
Commercially, those products are different. Once folded, however, their shipping dimensions may be close enough that one mailer performs well across most orders.
Producing separate boxes for small, medium and large garments would create more stock without solving much.
The same applies to compact cosmetics, soaps, accessories and many lightweight retail products.
A well-sized Custom Mailer Box can support several products when the packed footprint and protection needs are genuinely similar.
I would accept a sensible amount of clearance before introducing another custom size that is rarely used.
Simplicity matters while demand is still developing
I am cautious about creating too many sizes for a new product launch.
Forecasts are useful, but they do not always predict which products or combinations customers will actually order.
If you manufacture separate packaging for every launch item before those patterns become clear, you can end up holding cartons for slow-moving products while repeatedly running out of packaging for the products that sell.
This is one reason I favour fewer well-considered specifications early on. Custom Packaging for Small Business follows the same principle: give the business enough flexibility to learn what actually sells before locking money into unnecessary packaging stock.
When Another Box Size Earns Its Place
I would not add another carton because one product is 20 millimetres shorter than another.
I would add one when that dimensional difference repeatedly creates a real problem.
Too much filler is usually an early warning
Empty space often creates another task.
Someone adds paper.
Someone folds tissue several times.
Someone cuts cushioning.
Someone changes how the product sits so it does not move.
The universal box may look simple when ordering packaging, but the packing process is compensating for it.
There is nothing wrong with some clearance. You need room for board thickness, inserts, protective material and practical loading.
The problem is unnecessary space that has to be managed on almost every order.
Product movement can turn poor fit into damage
A strong carton cannot fully compensate for a product that moves freely inside it.
This matters particularly with:
If you can feel the contents slide or hit another component when the parcel moves, I would investigate the fit.
But I would not immediately order a smaller box.
First determine whether the outer carton is too large or whether the product needs better internal restraint.
Those are different problems.
Sometimes You Need a Better Insert, Not Another Box
This is one of the most useful checks before adding another outer size.
Imagine two gift sets with almost the same overall dimensions.
One contains two jars. The other contains a bottle, tube and accessory.
A second outer carton may add little value. Two different internal layouts inside one sensible carton could be easier to manage.
Custom Inserts and Dividers can control movement, separate products and create a more consistent presentation without automatically multiplying the outer cartons you hold.
I would consider this when the box itself is already reasonably sized but the contents need better positioning.
I would not use an insert simply to occupy a heavily oversized carton.
If half the box is unused, adding more material inside it usually hides the sizing problem rather than solving it.
How to Choose Packaging Inserts covers that decision in more detail, including product fit, material choice and when an insert genuinely earns its cost.
Compare the Complete Packed Cost, Not Just the Carton Price
This is where many box-size decisions go wrong.
One universal carton may have a lower unit price because all your volume goes into one specification.
That does not automatically make it cheaper to use.
I look at the complete packed order:
Imagine the universal carton costs less per unit but every small order needs extra paper and another 20 seconds of packing time.
The carton is cheaper.
The packed order may not be.
The opposite can happen too. A perfectly fitted additional box might save a little material but move so slowly that the business spends more time and space storing it than the saving is worth.
There is no useful rule saying fewer box sizes are always cheaper.
The operating cost has to decide.
Businesses using several structures can separate these jobs more clearly across Custom Boxes, rather than expecting one carton type to handle retail presentation, shipping and premium presentation equally well.
Product Packaging and Shipping Packaging Need Different Thinking
A product box fits an individual item.
A shipping carton fits the complete customer order.
Those two jobs should not automatically create the same number of sizes.
A skincare business might use different folding cartons for a serum, moisturiser and cleanser because the bottles need precise retail presentation.
All three products might still ship using two shared corrugated outer cartons based on the combinations customers normally buy.
The inner carton may need exact fit.
The shipping carton needs to handle the full packed order efficiently.
That distinction matters for cosmetics, candles, electronics, food products and many other product lines.
When transit protection drives the decision, Custom Shipping and Postal Boxes are the better place to think about board strength, outer dimensions and delivery performance.
I would not create a separate shipping box simply because every inner product carton has different measurements.
Shipping Air Can Cost More Than It Looks
An oversized box uses more than extra cardboard.
It occupies more parcel volume and usually needs more internal material to control movement.
For ecommerce businesses, that can affect freight economics as well as packing cost.
I do not recommend chasing a carton that touches the product on every side. Over-tight packaging can create its own problems.
The aim is controlled space.
If small orders repeatedly occupy only a fraction of the shipping carton, I would test a second size and compare the finished parcel.
Not just the empty box.
Not just the purchase price.
The complete order.
Packing Speed Is One of the Best Tests
Packaging is not finished when the cartons arrive at your business.
Someone still has to erect, fill and close them.
A box can look efficient on a specification sheet and perform badly at the packing bench.
I use a simple test.
Pack a normal order completely in the current box.
Then pack the same order using the proposed alternative.
Include:
Time the complete job.
Do not time an empty box.
A slightly more expensive carton can make sense if it removes several manual steps. Once order volume increases, seconds per parcel start to matter.
The reverse is also true.
Adding another size that saves a small amount of cardboard but slows stock selection or causes staff to pick the wrong carton may make the operation worse.
Storage Should Influence How Many Sizes You Keep
Every additional custom box needs physical space.
Five specifications do not simply mean five artwork files.
They can mean:
Corrugated boxes arrive flat, but large quantities still take space.
That is why I give simplicity more weight when the improvement from another size is small.
When another carton clearly reduces packing work, product movement or parcel volume across a large share of orders, the extra stock position becomes easier to justify.
Custom Packly can start from an MOQ of 50 while also supporting large production runs, repeat orders and volumes into thousands or tens of thousands. A lower minimum makes testing possible. It should not become a reason to create unnecessary sizes.
Variable-Depth Cartons Can Remove an Entire Size
Sometimes length and width stay fairly consistent while height changes.
That is where a multi-depth carton can work well.
Extra crease positions allow the packer to reduce the height of the same box depending on the contents.
The same footprint might therefore handle:
This can be more practical than stocking three separate cartons that differ mainly in depth.
It is less useful when products vary heavily in footprint, weight or protection needs.
Do not decide first that you want two boxes, three boxes or five boxes.
Let the product geometry and real order patterns decide.
A Practical Example of How I Would Group Ten Products
Imagine a business with ten products.
Four are small.
Three are medium.
Two are substantially larger.
The final product is a gift set.
I would not immediately create ten shipping boxes.
I would first test something more disciplined:
Then I would look for where that system performs badly.
Suppose one medium product becomes the bestseller and ships alone thousands of times. If every one of those orders needs filler because the medium carton is unnecessarily large, a dedicated size may now earn its place.
The product dimensions did not change.
The order volume changed the economics.
That is the sort of evidence I want before creating another printed specification.
Different Products Need Different Levels of Right-Sizing
The same amount of free space does not create the same risk for every product.
Clothing can usually tolerate more flexibility
Folded clothing is light and relatively resistant to impact.
A business may use one mailer for single garments and another for multi-item orders without creating a carton for every garment type.
Glass skincare products need more control
Bottles, pumps and jars have very different consequences if they move.
Here, I may put more work into the product carton or fitted insert while keeping the outer shipping assortment relatively simple.
Candles can make another size worthwhile sooner
A single candle and a three-candle set can differ sharply in packed weight and impact risk.
Trying to force both into one corrugated carton may require enough extra cushioning that a second size becomes the cleaner choice.
Subscription products depend on how predictable the contents are
If the packed dimensions stay similar every month, a dedicated box can become very efficient.
If each release changes dramatically, sizing everything around the largest possible month can create unnecessary volume for the rest of the year.
There is no universal answer because the physical behaviour of the product matters.
Use Real Order History Once You Have It
Once a business has enough sales data, I prefer evidence over assumptions.
Take a representative period of completed orders and group them by packed requirements.
You might find that:
Those percentages do not automatically tell you how many boxes to manufacture.
They tell you where to test.
Perhaps the smallest 45% justify their own carton.
Perhaps the medium size handles the next 30% efficiently.
Perhaps the remaining orders can share a larger shipping carton.
That is a stronger basis for packaging decisions than designing a new box around every item in the product list.
Test the Smallest and Hardest Order in Every Proposed Box
Do not approve a carton because the easiest order fits well.
Test the extremes.
For every proposed size, I would check:
The Dieline Tool can help establish structural dimensions before artwork is finalised, but a dieline cannot tell you everything about the finished packed order.
The physical pack still needs to behave properly when lifted, stacked, moved and delivered.
If board, print, inserts and structure all need to change together, Customisation is where those choices should be treated as one packaging decision rather than separate upgrades.
Five Box-Sizing Mistakes I Would Avoid
Using the largest product to determine every box
It looks simple but often leaves everyday smaller orders inside cartons designed around an exception.
Creating one custom size for every product
Exact fit is valuable.
Slow-moving printed inventory is not automatically valuable.
Group products when the physical requirements allow it.
Ignoring what customers buy together
A perfect single-product carton can become irrelevant when customers usually order bundles.
Outer shipping sizes should reflect complete orders.
Treating filler as free
Paper, tissue, cushioning, storage and labour all cost money.
If the same carton repeatedly needs extra material to make it usable, include that material in the comparison.
Trying to remove every millimetre of unused space
Right-sizing does not mean forcing the product into the smallest possible carton.
You still need practical tolerances for loading, board thickness and protection.
The objective is efficient fit, not theoretical perfection.
My Rule: Keep the Current Size Until Another One Proves Its Value
I do not think businesses should aim for the smallest possible number of boxes.
I also do not think every product deserves its own packaging specification.
Both extremes can cost more than they save.
Instead, make every proposed box size prove itself.
Does it remove a meaningful amount of filler?
Does it reduce product movement?
Does it make packing faster?
Does it improve parcel dimensions?
Does it solve a genuine presentation problem?
Will it be used often enough to justify another stock position?
If the answer is no, keep the current carton.
If the answer is clearly yes across a meaningful share of orders, test the additional size.
That is how I prefer to approach sizing at Custom Packly: start with the product, then look at real order combinations, protection, packing work, storage and total packed cost.
The right number of box sizes is the smallest number that can do those jobs properly.
FAQs About Choosing One or Multiple Box Sizes
How much empty space is acceptable inside a box?
There is no useful percentage that fits every product. A folded garment can tolerate more clearance than a glass bottle. Judge the space by what it causes. If it creates movement, excessive filler, slow packing or poor presentation, the fit needs attention.
Should every product have its own box size?
Usually not for shipping. Individual retail cartons may need precise dimensions, but several products can often share the same outer shipping carton. Base the outer sizing decision on the orders customers actually place.
Can inserts help me use fewer outer boxes?
Yes. If the outer carton is already sensibly sized, different inserts can adapt it to different products or sets. Inserts work especially well when the box dimensions are right but individual products need more restraint or separation.
When should I add a second or third box size?
Add one when the current carton causes the same problem often enough to matter. Repeated filler use, product movement, unnecessary parcel volume, slow packing and a high-volume product that consistently fits poorly are strong signals.
Should a new business start with fewer box sizes?
Often, yes. Early demand can differ from forecasts. Starting with fewer versatile sizes lets you see what customers actually order before committing money and storage space to several printed specifications.
Get Help Choosing the Right Number of Box Sizes
You do not need to decide the final carton dimensions before speaking to a packaging specialist.
The most useful information is your product dimensions, product weight, common order combinations, approximate quantities and anything you dislike about your current packaging.
From there, we can assess whether one carton works, whether another size earns its place or whether an insert or different structure would solve the problem more cleanly.
When you have those details, Get a quote and talk to a packaging expert about the smallest practical set of box sizes for the way your products are actually packed.
