Envelope Calculator — Calligraphy Envelope Layout

C5 (229 x 162 mm) is the most popular for UK wedding invitations, fitting an A5 card. DL (220 x 110 mm) is standard for letters. Square envelopes (155 x 155 mm) are popular for informal invitations but cost more to post.

Royal Mail recommends the delivery address sits in the centre area of the envelope, left-aligned (do not centre or stagger the individual lines), with a clear margin around it and kept clear of the stamp area in the top-right. For calligraphy, a slightly-left-of-centre, vertically-centred block looks balanced. Source: Royal Mail "A guide for letter envelope design and clear addressing" (Nov 2019).

A typical UK address has 5-6 lines: name, house number and street, locality (optional), town, county (optional), postcode. Always include the postcode on its own line or clearly separated.

Yes — Royal Mail recommends a return address on the back flap or top-left corner of the front. For calligraphy envelopes, the back flap is traditional for formal correspondence.

For DL and C6 envelopes, 3-4 mm x-height works well. For C5 and C4, you can go to 4-5 mm. The text should not look cramped or overwhelm the envelope. Always do a test layout before your final batch.