On this page 8 sections
What size poster you need comes down to three things: the space it’s going in, the distance your readers will be standing at, and whether it has to fit a frame or an A-board. For a door or noticeboard, A4 (210 × 297 mm) or A3 (297 × 420 mm) is usually right. Windows and corridors suit A2 (420 × 594 mm). Receptions, A-boards and exhibition walls call for A1 (594 × 841 mm) or A0 (841 × 1189 mm). Frames bought in the shops are often imperial, 20 × 30 in or 30 × 40 in, and outdoor poster sites use “sheet” sizes. Measure first, then pick.
Measure the space before you choose #
Grab a tape and measure the spot, or the inside of the frame. Then stand where your readers will be and pace out the gap. Those two numbers answer most of the question. A poster that fills a window but can’t be read from the pavement has failed, and so has one with perfect lettering that nobody notices because it’s lost on a big wall.
If it’s going in an existing frame or A-board, measure the poster opening, not the outside of the frame. Two frames that look alike can take different sizes.
Every size on our poster pages #
Our poster printing page covers eight sizes, smallest first:
| Millimetres | Name | Good spots for it |
|---|---|---|
| 148 × 210 | A5 | Countertops, small notices |
| 210 × 297 | A4 | Noticeboards, doors, small windows |
| 297 × 420 | A3 | Events, staff rooms, shop windows |
| 420 × 594 | A2 | Corridors, windows, pavement A-boards |
| 508 × 762 | 20 × 30 in | Ready-made frames, film and event posters |
| 594 × 841 | A1 | Reception areas, exhibitions, A-boards |
| 762 × 1016 | 30 × 40 in | Big frames, in-store displays |
| 841 × 1189 | A0 | Large displays, exhibition walls |
The four most popular sizes each have a page of their own: A3, A2, A1 and A0. For the whole A series, including A6 and A7, see our chart of A sizes in millimetres.
What size poster for an A-board? #
Pavement A-frames take either A2 or A1 posters, and one won’t fit the other. Measure the window on your frame or check its paperwork before ordering. If the frame’s fine and you just need fresh artwork, A-frame replacement posters come in both sizes, and you can have a different design on each face.
Billboards and outdoor sites #
Roadside and street poster sites measure in “sheets”, a leftover from the days when a big poster went up in pasted sections. Among our billboard posters:
- The 4 sheet measures 1016 × 1524 mm.
- The 6 sheet measures 1200 × 1800 mm. It’s the upright format you’ll spot in plenty of bus shelters and roadside panels.
- Bigger 48 and 96 sheet options are on the product page too.
The largest boards are built from several panels, and each site owner decides the precise dimensions and panel split, so check their specification against the product page first. Paper choices are 150gsm satin or 120gsm blueback. Express gets billboard posters out in 3 working days, Standard in 5 and Saver in 7.
Need something tougher for street furniture or an event? Correx poster boards put your poster on rigid plastic that doesn’t mind rain.
Which material for where #
Every poster size above comes in four materials. Choose by where it’ll hang:
- 150gsm satin poster paper: frames and indoor walls. Smooth, a gentle sheen, good colour.
- 120gsm blueback: posters pasted up outdoors. The blue back stops old posters underneath from showing through.
- 400gsm PVC-free: indoor or sheltered spots where paper would get battered.
- 440gsm PVC: outside and likely to get wet, fixed with cable ties or clips rather than paste.
Going outside? Our waterproof posters run from A4 up to A0, printed on either 440gsm PVC or 400gsm PVC-free. Paper posters leave in 2 working days with Express, 4 with Standard and 6 with Saver.
Match the words to the distance #
A handy sign-trade rule: allow 25 mm of capital height per 3 m your reader stands back. Set against the usual spots for each size:
- A4 on a door: capitals 15 to 25 mm, for readers 1 to 3 m off.
- A3 in a window: capitals 20 to 42 mm, readers 2 to 5 m off.
- A2 down a corridor: capitals 25 to 67 mm, readers 3 to 8 m off.
- A1 on an A-board: capitals 42 to 83 mm, readers 5 to 10 m off.
- A0 at an exhibition: capitals 67 to 125 mm, readers 8 to 15 m off.
If your headline won’t fit at the height it needs, you’ve picked too small a poster, or too many words. Turning millimetres into font sizes is covered in our guide to sign text size. Keep it to a headline, a couple of supporting lines and a single call to action.
A worked example
Say you run a cafe and want a poster in the window that people across a quiet street, roughly 9 m away, can read. The rule gives headline capitals of about 75 mm. At that height, a bold font fits roughly nine to eleven letters across an A1 (594 mm wide), and only around half that on an A3 (297 mm wide). “Breakfast served all day” splits neatly into three short lines on the A1 (“Breakfast”, “served”, “all day”) with space left for a smaller line underneath. On the A3, “Breakfast” alone wouldn’t fit on one line. So the answer to what size poster here is A1, or a much shorter message on something smaller.
Artwork setup in brief #
- Bleed: give every edge an extra 3 mm, which makes an A2 page 426 × 600 mm.
- Leave words a little way in from the trim so nothing gets clipped.
- Close-up sizes like A4 and A3 want photos at 300 dpi at finished size; A1, A0 and larger are fine at 150.
- PDF is best, with fonts embedded or turned to outlines. The full list lives in our artwork guidelines, and someone checks every uploaded file for free.
Putting posters up outdoors #
Your own building, notice boards and licensed advertising sites are all fine. Putting posters on walls, lamp posts or hoardings that belong to someone else can break the rules on advertising; for England, the Town and Country Planning (Control of Advertisements) (England) Regulations 2007 set out what needs consent. Your local council can tell you more.
Still torn on what size poster to go for? Tell us where it’s going and how far back people will stand through the contact form, and we’ll suggest a size and a material.