Royal Mail Letter Sizes


Royal  Mail Letter Sizes


Our useful guide below will help you to determine letter sizes and the cost of UK postage including the latest information and services from Royal Mail.



Greeting cards, personal letters, postcards, C5 envelopes and bills usually fall into the letter category.


Letter dimensions:

Length: 24cm max

Width: 16.5cm max

Thickness: 0.5cm max

Weight: 100g max


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Large Letter.jpg

Large Letters

The large letter format covers items like A4 documents, CDs and DVDs in their cases, certificates, some large greeting cards with badges and most magazines.

Large Letter dimensions:

Length: 35.3cm max

Width: 25cm max

Thickness: 2.5cm max

Weight: From 100g to 750g max


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Posters or other rolled item dimensions:

Length: 90cm max

The length plus twice the diameter must be no more than 104cm


Items over the dimensions listed above should be sent by Standard Parcels.



If your item is over the maximum size or weight for the small or large letter format, you will need to send it as a 1st class or 2nd class parcel or by Parcelforce Worldwide if it's a large parcel.

Small Parcel dimensions:

Length:  45cm max

Width:    35cm max

Thickness:  16cm max

Medium Parcel dimensions:

Length:  61cm max

Width:    46cm max

Thickness:  46cm max

Large Parcel dimensions:

Length:  1.5 metres max and the length and girth combined should not exceed more than 3 metres

Weight:  30kg max. Only available on Parcelforce Worldwide services.



Click here to use our helpful envelope selector to choose the right products for your posting needs. The parcel dimensions listed above is up to an ideal size provided that the combined length and girth does not exceed 3m. For more information on Royal Mail, including its products and services, please visit


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