The Complete Guide to Choosing the Right Single Wall Box Size
Choose the right box size for your products: the complete sizing guide.
How to measure for boxes
Sizing steps0 / 4 checked
Quick answer
Measure your product, add 20-30mm per side for void fill, and select the closest standard size. Stock 6-8 sizes to cover your product range. The box should hold the product with enough room for void fill on all sides but not so much that excessive fill is needed. Internal dimensions are what matters for fit. External dimensions determine shipping cost. Test-pack your most common products before ordering in bulk.
Building a size range
The optimal balance of coverage and inventory.
Size boxes around your most-shipped items.
15-30% cost reduction from proper sizing.
Cost: case study or shipping costs.
Postal considerations
Royal Mail small parcel maximum is 61x46x46cm. Standard carrier limits vary. Dimensional weight (LxWxH/5000) determines shipping cost when it exceeds actual weight. Smaller boxes cost less to ship.
Frequently asked questions
Measure product, add 20-30mm per side, choose closest standard size.
6-8 for most product ranges.
Most items ship in oversized boxes, wasting void fill and shipping cost.
Internal for product fit. External for shipping cost.
Always, before ordering in bulk.
Part of our guide
Product Guide: Single Wall Cardboard Boxes
Expert guides on single wall cardboard boxes for shipping, storage, and e-commerce packaging.
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