Medium Box Dimensions: A Complete Guide to Standard Shipping and Packaging Sizes

Not all boxes are built the same—and that matters more than you think. Whether you’re shipping clothing, tech accessories, or cosmetics, choosing the right box dimensions can save money, protect your products, and improve the unboxing experience.

This comprehensive guide dives deep into standard and medium-sized box dimensions, how to measure box height, width and length correctly, and why the size of your box can impact everything from shipping costs to brand perception.

Understanding Box Dimensions: Height, Width, Length Explained

Before you order packaging, it’s important to understand how do you measure box dimensions. The standard format is:

Length × Width × Height (L × W × H)
All measurements are in millimetres (mm) or centimetres (cm) unless otherwise stated.

• • Length (L) – the longest side when the box is placed flat

• • Width (W) – the side adjacent to the length

• • Height (H) – the vertical dimension from base to top when the box is upright

Knowing these basics ensures you’re ordering the right box with dimensions that fit your product snugly—without wasted space or excess postage.

What Is a Medium-Sized Box?

A medium box sits between small parcels and large cartons—perfect for shipping mid-weight goods like books, electronics, cosmetics, or multiple smaller items.

Common Medium Box Dimensions (UK)

Use Case	Box Dimensions (mm)	Description
Standard Medium Shipping Box	400 × 300 × 200 mm	Ideal for general e-commerce shipments
Medium Flat-Pack Box	430 × 320 × 160 mm	Great for apparel and books
Double-Wall Medium Parcel Box	406 × 305 × 254 mm	Extra protection for heavier items
Royal Mail Medium Parcel (Max)	610 × 460 × 460 mm	Maximum limit for medium-sized category
Medium Box for Home Moves	508 × 406 × 406 mm	Popular for removals and storage

Looking for custom packaging tailored to your products? Explore our Flat-Pack Ecommerce Boxes or Cardboard Shipping Boxes for more options.

Industry Use Cases for Medium Box Dimensions

Medium-sized cardboard boxes offer flexibility across multiple sectors:

E-Commerce Retail:

Ideal for clothing, shoes, books, skincare bundles or tech accessories. These boxes optimise postage costs while offering enough space for branding and filler.

Office & Stationery:

Medium boxes are often used for shipping A4 paper reams, document folders, and desktop supplies.

Subscription Boxes:

Whether monthly beauty kits or snack boxes, medium dimensions allow products to sit securely with padding.

Logistics & Warehousing:

A standard medium box size streamlines stacking, loading and order picking in warehouses and delivery hubs.

House Removals:

Home movers rely on medium moving boxes for books, kitchenware and household items.

How to Choose the Right Medium Box Size for Shipping?

Selecting the correct shipping box dimensions prevents damage and reduces void fill. Here’s what to consider:

• • Product Dimensions – Measure the item (plus wrap/padding) carefully.

• • Weight – Use double-wall boxes for items over 10kg.

• • Delivery Method – Some couriers have box size restrictions.

• • Stackability – Square, rigid boxes make loading and warehousing more efficient.

• • Branding – A well-fitted box looks cleaner and feels more premium.

Remember: A box that’s too big leads to higher courier fees and excessive packaging waste. A box too small risks product damage.

Need Custom Box Sizes?

At  Buy Packaging Boxes, we help brands create the perfect box size for every product. Whether you’re after a single-wall shipper or a luxury rigid box, we’ll manufacture to your exact box measurements.

Our Offerings Include:

• • Custom box sizing (L×W×H)

• • Digital proofing and free design support

• • Branded prints or plain Kraft options

• • Low minimum order quantities

• • Eco-friendly board options

Frequently Asked Questions (FAQs)

What are the dimensions of a medium-size box?

A typical medium cardboard box measures around 400 × 300 × 200 mm, though sizes can vary by industry use.

What size is a medium parcel box?

According to Royal Mail, a medium parcel can be up to 610 × 460 × 460 mm with a max weight of 20kg.

What is the size of a medium carton box?

Common carton sizes for medium loads include 430 × 320 × 160 mm or 508 × 406 × 406 mm, depending on product type.

What can fit in a medium box?

Medium boxes are great for multiple clothing items, shoes, cosmetics sets, kitchenware, books, and electronics.

Where can I order medium-sized boxes with specific dimensions?

You can order from Buy Packaging Boxes —we offer fully customisable box dimensions to match your exact product size.

Conclusion: Get the Right Box, Every Time

Choosing the correct medium box dimensions ensures cost-efficient shipping, better protection, and a professional unboxing experience. By knowing your product size and packaging needs, you can avoid common pitfalls and build a better brand experience.

At Buy Packaging Boxes, we help UK brands find the perfect-fit box—whether it’s off-the-shelf or entirely custom. From shipping box sizes to branded cardboard boxes, we’ve got your dimensions covered.

Ready to find your box? Get a free quote now or browse our full range of cardboard packaging solutions.