UK paper size guide
Need a measurement quickly? A4 is 210 × 297 mm, A3 is 297 × 420 mm and A2 is 420 × 594 mm.
Use this complete A0-A10 chart to compare paper sizes in millimetres, centimetres and inches, then find out which size and frame will suit your print.
Quick reference
A-series paper size chart
Dimensions are shown as width × height in portrait orientation. Reverse the numbers for landscape orientation. Use millimetres when an exact fit matters.
| Paper size | Millimetres (mm) | Centimetres (cm) | Inches (approx.) | Common uses |
|---|---|---|---|---|
| A0 | 841 × 1189 | 84.1 × 118.9 | 33.1 × 46.8 | Large posters, plans and displays |
| A1 | 594 × 841 | 59.4 × 84.1 | 23.4 × 33.1 | Posters, charts and presentations |
| A2 | 420 × 594 | 42.0 × 59.4 | 16.5 × 23.4 | Medium posters, notices and artwork |
| A3 | 297 × 420 | 29.7 × 42.0 | 11.7 × 16.5 | Small posters, menus and diagrams |
| A4 | 210 × 297 | 21.0 × 29.7 | 8.3 × 11.7 | Documents, notices and certificates |
| A5 | 148 × 210 | 14.8 × 21.0 | 5.8 × 8.3 | Leaflets, table signs and small notices |
| A6 | 105 × 148 | 10.5 × 14.8 | 4.1 × 5.8 | Postcards, flyers and counter signs |
| A7 | 74 × 105 | 7.4 × 10.5 | 2.9 × 4.1 | Tickets, labels and pocket cards |
| A8 | 52 × 74 | 5.2 × 7.4 | 2.0 × 2.9 | Small cards and labels |
| A9 | 37 × 52 | 3.7 × 5.2 | 1.5 × 2.0 | Tiny labels and notes |
| A10 | 26 × 37 | 2.6 × 3.7 | 1.0 × 1.5 | Very small labels |
Inch measurements are rounded to one decimal place. A-series trimmed paper sizes are specified by ISO 216.
Interactive size checker
What paper size do I have?
Enter the width and height of your print. We will compare it with A0-A10 and several common photo, poster and US sizes.
Your result
Enter two measurements to find the closest recognised format.
Portrait and landscape measurements are both accepted.
Check your measurements
Enter a width and height greater than zero.
× mm ()
Your measurements match this format to within 1 mm on each side.
Your print differs by approximately mm on the short side and mm on the long side.
This is not a close standard match. The nearest format is shown for comparison, but you may need a custom frame or mount.
Understand the sequence
How A paper sizes compare
Every A size keeps the same proportions. Fold or cut an A3 sheet in half across its longest side and you get two A4 sheets. Put two A4 sheets together along their longest sides and you get one A3 sheet.
Remember: the area doubles or halves at each step. The individual side lengths do not simply double.
Popular formats
A0, A1, A2, A3, A4, A5 and A6 sizes
A0
841 × 1189 mm
84.1 × 118.9 cm · 33.1 × 46.8 in
The largest standard A-series sheet, commonly used for large posters, plans and high-impact displays.
A1
594 × 841 mm
59.4 × 84.1 cm · 23.4 × 33.1 in
A popular poster size for exhibitions, schools, retail displays and public information.
A2
420 × 594 mm
42.0 × 59.4 cm · 16.5 × 23.4 in
Strong visibility for posters and artwork without using as much wall space as A1.
A3
297 × 420 mm
29.7 × 42.0 cm · 11.7 × 16.5 in
Well suited to posters, menus, diagrams, timetables and notices read from a short distance.
A4
210 × 297 mm
21.0 × 29.7 cm · 8.3 × 11.7 in
The standard UK format for documents, letters, notices and office printing.
A5
148 × 210 mm
14.8 × 21.0 cm · 5.8 × 8.3 in
Common for leaflets, table notices, small signs, notebooks and invitations.
A6
105 × 148 mm
10.5 × 14.8 cm · 4.1 × 5.8 in
Often used for postcards, flyers, counter signs and compact information cards.
Is A4 the same as US Letter?
No. US Letter is 8.5 × 11 inches (about 216 × 279 mm), so it is slightly wider and shorter than A4. A frame made for one format may not fit the other correctly.
Common question
Is 5 × 7 the same as A5?
No. A 5 × 7 inch print is smaller than A5 in both directions.
A 5 × 7 print placed in an A5 frame will leave a gap unless you use a suitable mount. Match the frame or mount opening to the actual print measurements for a precise result.
- 5 × 7 print
- 127 × 177.8 mm · 12.7 × 17.78 cm · 5 × 7 in
- A5 paper
- 148 × 210 mm · 14.8 × 21 cm · about 5.8 × 8.3 in
Practical display advice
Which paper size should I choose for a poster?
Choose according to the viewing distance, available wall space and how much information the design contains.
- A4-A3Notices, menus and messages viewed close up.
- A2Medium wall posters and promotional graphics.
- A1Prominent posters in busy indoor spaces.
- A0Large campaigns, plans and high-impact displays.
How to measure a print for a frame
- 1Remove the print and lay it flat.
- 2Measure its width and height in millimetres without including an existing frame.
- 3Compare both measurements with the chart above.
- 4Decide whether the print will sit directly in the frame or behind a mount.
- 5Check the product's graphic size, visible area and overall size before buying.
Display specialists since 1995
Need a frame for your print?
Green Magic has helped UK organisations choose practical poster frames and sign displays for more than 30 years.
Useful answers
Paper size questions
What size is A4 in centimetres?
A4 is 21.0 × 29.7 cm. It is 210 × 297 mm or approximately 8.3 × 11.7 inches.
What size is A3 in centimetres?
A3 is 29.7 × 42.0 cm. It is 297 × 420 mm or approximately 11.7 × 16.5 inches.
What size is A5 in centimetres?
A5 is 14.8 × 21.0 cm. It is 148 × 210 mm or approximately 5.8 × 8.3 inches.
Is A3 double the size of A4?
Yes, A3 has twice the area of A4. Its side lengths are 297 × 420 mm rather than twice each A4 side.
Is A5 bigger or smaller than A4?
A5 is smaller and has half the area of A4. A5 is 148 × 210 mm; A4 is 210 × 297 mm.
Is 30 × 40 cm A3?
Not exactly. A3 is 29.7 × 42.0 cm. A 30 × 40 cm print is 2 cm shorter, so it may need a mount or a frame made specifically for 30 × 40 cm prints.
Are paper dimensions written width first?
Yes. Dimensions are normally width × height. Portrait A4 is 210 × 297 mm; landscape A4 is 297 × 210 mm.