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Letter Size A Short Guide

Mailboxshop24 offers letterboxes in various colors, shapes, materials and sizes. If you already know that you regularly receive for example, very large envelopes, you should already take this into account when selecting your mailbox.

It is important to select the correct size postbox and mail slot best suited to the size of post your normally receive. To make the selection a little easier, both paper and mailbox sizes are subject to specific standards. Basically, the postbox size should be slightly larger than the contents. If you have a large amount of post please consider a larger postbox. This not only looks better and more professional, it also protects the contents. You've probably already been annoyed about post that has arrived damaged and in poor condition.

Here is a little help most common envelope sizes:

DIN B series: Suitable for approx. 5 - 8 sheets

Name Space for sheets Size Suitable Letterbox
DIN B6 2 x folded DIN A4 sheet / postcard 125 x 176 mm Letterbox Rondello
DIN B5 1 x folded DIN A4 sheet 176 x 250 mm Letterbox Bologna
DIN B4 1 A4 sheet 250 x 353 mm Letterbox Trend


DIN C series: suitable for up to 5 sheets

Name Space for sheets Size Suitable Letterbox
DIN C6 2 x folded DIN A4 sheet / postcard format 114 x 162 mm Letterbox Udine
DIN C5 1 x folded A4 sheet 162 x 229 mm Letterbox Eleganza
DIN C4 1 DIN A4 sheet 229 x 324 mm Letterbox Wörthersee


Special formats:

Name Space for sheets Size Suitable Letterbox
DIN long Up to 3 sheets DIN A4 110 x 220 mm Letterbox Brighton
DIN c6/5 Up to 6 sheets Din A4 114 x 229 mm Letterbox Kensington


For other sizes of post and envelopes, e.g. square or oversized envelopes; these are not subject to any standard but are based on the provisions for the carriage of letters.
If in doubt, then try which envelope mailbox slot that is best for your mail.

Please call us for help and advice 0121 361 3607

The paper sizes are specified (in Europe) in the format series DIN A and in ISO 269. The formats of the envelopes are specified in DIN 678.
The A0 bow has an area of one square meter. By respective division of the paper, the other sizes move upward. (So A0 is the biggest paper in this spreadsheet and A10 is the smallest paper.

Here is a brief overview of the DIN A series:

Name Description Format Size (m²)
A0 quadruple Bow 1189 x 841 mm 1,000
A1 Double Sheet 841 x 594 mm 0,500
A2 Arc 594 x 420 mm 0,250
A3 Semicircle 420 x 297 mm 0,125
A4 Quarter sheet/Letter 297 x 210 mm 0,063
A5 Eight Sheet/Letter 210 x 148 mm 0,032
A6 Half Sheet/Postcard 148 x 105 mm 0,016
A7 Quarter Sheet 105 x   74 mm 0,008
A8 Half Sheet 74 x   52 mm 0,004
A9 37 x   52 mm 0,002
A10 26 x   37 mm 0,001


Graphic DIN-Formats:

Briefkastenshop24 Formate DIN-A

If you also want to be sure that your parcels are always delivered to the right place, then we recommend that you buy a parcel post box, such as a letterbox. the Parcel Keeper.

We are confident at Mailbox24. That you will find the mailbox that suits you

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