Envelope Size Guide UK

Looking for the right sized envelope? Our easy to use size guide will help you chose the perfect sized envelope for your needs. The below guide will help you understand which envelope you need to accommodate your greetings cards, invitations, latest mailing or project.

Envelope Size in mm Size in cm Size in inches Fits
C4 Envelopes 229 x 324 22.9 x 32.4 9.01 x 12.75 A4 sized document
C5 Envelopes 162 x 229 16.2 x 22.9 6.37 x 9.01 A5 sized document
C6 Envelopes 114 x 162 11.4 x 16.2 4.48 x 6.37 A6 sized document
DL Envelopes 110 x 220 11 x 22 4.33 x 8.66 Compliment slips or A4 folded
130 mm Square Envelopes 130 x 130 13 x 13 5.12 x 5.12 Small greetings cards or invitations.
155 mm Square Envelopes 155 x 155 15.5 x 15.5 6.10 x 6.10 Medium sized greetings cards or invitations.
160 mm Square Envelopes 160 x 160 16 x 16 6.29 x 6.29 155mm square card blank.

A simple way of remembering which envelope fits what sized document is to swap the A for C. For example if you require an envelope to fit an A5 document you would swap the A5 to C5, meaning the envelope you require would be C5.

C4 Envelope Size Guide

A standard C4 envelope measures 229 x 324 mm. C4 envelopes will accomodate unfolded A4 paper. These are perfect to fit business documents, certificates and more. These are also known as A4 envelopes.

C5 Envelope Size Guide

A standard C5 envelope measures 162 x 229 mm and will accomdate either A5 sized paper/card or A4 sized folded in half. These are perfect for regular sized greetings cards and invitations. Also known as C5 envelopes.

C6 Envelope Size Guide

A standard C6 envelope measures 114 x 162 mm and will accomdate either A6 sized paper/card, A5 sized paper/card folded in half or A4 sized folded in quarters. Great for greetings cards, invitations and mailings. Also known as A6 envelopes.

DL Envelope Size Guide

A standard DL envelope measures 110 x 220 mm and will accomdate a compliments slip or A4 paper/card folded into three. These are traditional envelopes used in everyday post to enclose A4 paper documents and are especially popular as use for business envelopes for sending letters in.