Royal Mail Parcel Sizes Guide 2024

The Royal Mail size and weight guide for the UK is a handy reference of the standard dimensions of letters and parcels in the UK for when you are sending products through the post.

Knowing the size of your packaging is important as if you are sending goods in packaging that is larger than needed could cost you a lot of money in the long run.

The Royal Mail splits the level of postage charges between letters and parcels.

The two different sizes of letter are ‘Letter’ and ‘Large Letter’. There are three types of parcel size: ‘Small Parcel’, ‘Medium Parcel’ and ‘Large Parcel’.

Buy Parcel Boxes

Royal Mail Parcel Sizes – UK

Format Max weight Max length Max width Max thickness/depth
Small Parcel 2kg 45cm 35cm 16cm
Medium Parcel 20kg 61cm 46cm 46cm
Parcelforce Parcels 30kg 1.5m 3m length and depth combined
Parcelforce Large Parcels 30kg 2.5m 4m length and depth combined
Tubes Length of the item plus twice the diameter must be less than 104cm, with the greatest dimension less than 90cm.

Royal Mail Small Parcels

Royal Mail small parcels are up to 450mm x 350mm x 160mm in size with a maximum thickness of 160mm and a weight limit of 2Kg.

The small parcel size would allow you to send a candle for example in an 0201 single wall box with inner dimensions of 152 x 152 x 102mm. You could also send a subscription box in an 0426 die cut box (inner size 250 x 200 x 100mm).

We offer a selection of Royal Mail small parcel boxes that fit in the current limits of the small parcel size.

Medium Parcels

Royal Mail medium parcels are up to 610mm x 460mm x 460mm in size with a maximum thickness of 460mm and a weight limit of 20KG.

In terms of size, the boxes we recommend for 13 inch laptops would easily stay under the size limit, unless you have a lightweight laptop that weighs under 2KG, you will be charged for a medium parcel.

Large Parcels (Parcelforce Parcels)

Royal Mail large parcels are classed as bigger than 610mm x 460mm x 460mm in size or weigh in at more than 20KG.

Our double walled large boxes are ideal for transporting heavier goods being both sturdy and durable.

What is the Biggest Size Parcel the Post Office Will Take?

The biggest parcel the Royal Mail Post Office will take is one not larger than 2.5m length and 4m length and girth combined that weighs 30kg or less. “Parcelforce large parcels” are sent via ParcelForce Worldwide.

Custom Parcel Boxes

We can produce custom sized packaging that not only will make sure you’re sending your goods in the optimal sized box but also provide your customers with a unique branding experience.

Royal Mail Letter Sizes – UK

Format Max weight Max length Max width Max thickness/depth
Letter 100g 24cm 16.5cm 5mm
Large Letter 750g 35.3cm 25cm 2.5cm

Letter Size

Royal Mail letters have a maximum length of 240mm, a maximum width of 165mm with thickness up to 5mm and a weight no more than 100g.

First class letter size and second class letter size are exactly the same.

The Royal Mail classes letters as items such as greetings cards, personal letters, postcards and bills.

Large Letter Size

Royal Mail large letters have a maximum length of 353mm, a maximum width of 250mm with thickness up to 25mm and a weight no more than 750g.

Mail lite envelopes that fit the large letter dimensions would be perfect for sending a DVD or a mobile phone as they contain bubble wrap to protect the goods and also will be cheaper to send than a box.

We also sell large letter postal boxes (also known as Royal Mail PIP boxes). Large letter boxes fit into the large letter size pricing category so can save you money when posting fragile goods.

Items that fall into the large letter size typically include magazines, CDs, DVDs certificates and large greetings cards that might be A4 sized.

Royal Mail Prices – Updated October 2023

Here you will find details of Royal Mail parcel prices and Royal Mail letter sizes.

Royal Mail have produced a Business Price Guide (updated October 2023) that contains parcel and letters pricing and also details of other services such as franking and internal postage.

Personal customers and marketplace seller prices are covered by their UK and International parcel and letter service prices guide (updated October 2023)

Royal Mail online prices can be found in their online UK parcel and letter price guide (updated October 2023).

Royal Mail UK Standard Prices

Royal Mail 1st Class and 2nd Class UK Standard
1st Class 2nd Class
Royal Mail Sizes Weight up to and including Price Price
Letter 100g £1.25 75p
Large Letter Price and Weight 100g £1.95 £1.55
 250g  £2.60 £2.30
500g £3.20 £2.60
750g £3.20 £2.60
Small Parcel Prices 2kg £3.69 £2.99
Medium Parcel Prices 2kg £5.29 £4.49
10kg £6.99 £5.99
20kg £10.99 £9.49
Includes compensation up to £20 £20

Prices are exempt from VAT. Prices last checked 4 April 2023.

For more information on Royal Mail parcel prices and letter prices including UK Guaranteed (Special Delivery) and UK Signed please check out the Royal Mail Price Guide (updated October 2023).

Looking to end your package via DPD? We’ve also produced a guide to DPD Parcel Sizes.

Buy Parcel Boxes

Useful Size Guides for Boxes, Packages and Parcels


More Guides

Cardboard Box Dividers
Keep your products safe in transit Cardboard box dividers make it easy to pack multiple products into a single box. They are p...
Read More
Custom Boxes With Logo
Having your logo on a custom printed box is the ideal way to take your branding to the next level. Custom packaging featuring yo...
Read More
Calculating the Volume of a Box
Knowing the size of a cardboard box is essential to you working out your packaging requirements. The dimensions of the boxes w...
Read More
Digital Printing On Boxes
Digital printing on boxes has many advantages if you are looking for custom branded packages. In general there are very low set ...
Read More