UK Paper Sizes Explained: A0 to A7 Dimensions in mm, cm & Inches

UK paper sizes follow the ISO 216 "A-series": each size is exactly half the one above it, folded across the long edge. A4 is 210 × 297mm, A5 is 148 × 210mm, and the system runs from A0 (poster-sized) down to A7 (ticket-sized).

Paper size chart (mm, cm, inches)

Size	mm	cm	inches	Common uses
A0	841 × 1189	84.1 × 118.9	33.1 × 46.8	large posters, plans
A1	594 × 841	59.4 × 84.1	23.4 × 33.1	window posters, displays
A2	420 × 594	42.0 × 59.4	16.5 × 23.4	retail posters
A3	297 × 420	29.7 × 42.0	11.7 × 16.5	posters, menus, plans
A4	210 × 297	21.0 × 29.7	8.3 × 11.7	letters, documents, posters
A5	148 × 210	14.8 × 21.0	5.8 × 8.3	flyers, booklets, invites
A6	105 × 148	10.5 × 14.8	4.1 × 5.8	postcards, handouts
A7	74 × 105	7.4 × 10.5	2.9 × 4.1	tickets, loyalty cards
DL	99 × 210	9.9 × 21.0	3.9 × 8.3	rack leaflets, envelope inserts

DL isn't an A-size — it's one third of A4, made for standard business envelopes.

How the A-series works

Halve any size across its long edge and you get the next size down: two A5s make an A4, two A4s make an A3. Every size keeps the same 1:√2 proportions, which is why artwork scales cleanly between sizes with no cropping.

Which size for which job?

• Flyers & handouts: A5 (the UK standard) or A6 for volume street distribution — see the flyer pricing guide
• Posters: A3 for windows and boards, A2–A0 for distance viewing — see the poster guide
• Booklets & programmes: A5 finished (printed on A4 folded) — see the booklet guide
• Letterheads & documents: A4
• Rack leaflets & mailers: DL

FAQs

What size is A4 in mm? 210 × 297mm (21 × 29.7cm, or 8.3 × 11.7 inches).

What size is A5? 148 × 210mm — exactly half of A4. It's the standard UK flyer size.

Is A5 bigger than A6? Yes. Lower numbers are bigger: A5 (148 × 210mm) is double the area of A6 (105 × 148mm).

What is DL size? 99 × 210mm — one third of an A4 sheet, sized to fit a standard DL envelope without folding.

What size should my print file be? Final size plus 3mm bleed on every edge — an A5 flyer file is 154 × 216mm. Full setup rules in the print file setup guide.