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An A3 poster is 297 x 420mm, which is 29.7 x 42cm or 11.7 x 16.5 inches: twice the size of an A4 sheet. It is the smallest standard poster size, made for noticeboards, staff rooms, small windows and framed menus. We print A3 posters in the UK single-sided, from one poster, on 170gsm silk paper as standard, and a single A3 poster on it costs £16 including VAT, with free delivery to UK mainland addresses.
A3 poster size
| Measurement | A3 poster |
|---|---|
| Millimetres | 297 x 420mm |
| Centimetres | 29.7 x 42.0cm |
| Inches | 11.69 x 16.54in |
| Area | 0.125 square metres |
| Artwork size with 3mm bleed | 303 x 426mm |
| Safe area | Text and logos 10mm inside the trim |
| Pixels at 150dpi (finished size) | 1754 x 2480px |
| Pixels at 300dpi (finished size) | 3508 x 4961px |
| Pixels at 300dpi (with bleed) | 3579 x 5031px |
Inches are millimetres ÷ 25.4, and pixels are inches x dpi, rounded. The A3 poster page has the specification and live prices.
A3 compared with A4 and A2
A3 is two A4 sheets side by side, and two A3 sheets make one A2. Every A size in ISO 216 has the same shape, so an A4 design scales up to A3 at 141% without cropping, and an A3 design scales to A2 at 141% or to A1 at 200%.
| Size | Millimetres | Compared with A3 |
|---|---|---|
| A4 | 210 x 297mm | Half the area |
| A3 | 297 x 420mm | - |
| A2 | 420 x 594mm | Twice the area |
| A1 | 594 x 841mm | Four times the area |
| A0 | 841 x 1189mm | Eight times the area |
Our poster sizes guide explains how the four poster sizes compare and which to choose for each place.
What A3 posters are good for
A3 is read from a few steps away, so it suits a headline, a picture and a date, or a short list:
- noticeboards in schools, clubs, offices and community halls;
- staff rooms, kitchens and back-of-house notices;
- small shop windows, doors and till points;
- framed menus, price lists and room signs;
- event posters handed to venues and local shops to put up;
- photo and art prints.
A3 is also easy to share around: shops and venues are more likely to find room for an A3 poster than for an A2.
Why order A3 posters rather than print them at the office?
Many office printers only take A4 paper, and many cannot print right to the edge of the sheet. Our posters print to the edge of the sheet, because the artwork includes bleed that is trimmed off, and our standard 170gsm silk is heavier than office paper.
Our A3 paper: 170gsm silk as standard
We print A3 posters in full colour on one side of 170gsm silk paper. Silk is a coated paper with a low sheen: photos and colours stay crisp, and the poster has less glare than gloss under office and shop lights. You can also choose 135 or 250gsm silk, 135, 170 or 250gsm gloss, or 150gsm satin.
A3 posters are cut to the exact A size, so they fit frames and clip frames sold as A3.
Silk, gloss and satin posters are for indoor use. For A3 outdoors, choose 115gsm blueback, a billboard paper for pasting up outside, or 170gsm waterproof PVC; for a rigid outdoor sign, a correx board stands up to rain. For a rigid A3 sign indoors, see foamex boards. If you need a handout rather than a poster, our leaflets go up to A4.
A3 poster prices
Prices include VAT at 20% and free delivery to UK mainland addresses, read from our live price list.
| Quantity | Order total | Price per poster |
|---|---|---|
| 1 | £16 | £16.00 |
| 5 | £22 | £4.40 |
| 10 | £25 | £2.50 |
| 25 | £27 | £1.08 |
| 50 | £31 | 62p |
| 100 | £37 | 37p |
Each design is priced separately, so ten different A3 posters are ten items of one. The same quantities in every poster size:
| Quantity | A2 (420 x 594mm) | A3 (297 x 420mm) | A1 (594 x 841mm) | A0 (841 x 1189mm) |
|---|---|---|---|---|
| 1 | £19 £19.00 each £15.83 ex VAT | £16 £16.00 each £13.33 ex VAT | £21 £21.00 each £17.50 ex VAT | £35 £35.00 each £29.17 ex VAT |
| 5 | £33 £6.60 each £27.50 ex VAT | £22 £4.40 each £18.33 ex VAT | £40 £8.00 each £33.33 ex VAT | £70 £14.00 each £58.33 ex VAT |
| 10 | £36 £3.60 each £30.00 ex VAT | £25 £2.50 each £20.83 ex VAT | £48 £4.80 each £40.00 ex VAT | £89 £8.90 each £74.17 ex VAT |
| 25 | £46 £1.84 each £38.33 ex VAT | £27 £1.08 each £22.50 ex VAT | £78 £3.12 each £65.00 ex VAT | £191 £7.64 each £159.17 ex VAT |
| 50 | £50 £1.00 each £41.67 ex VAT | £31 62p each £25.83 ex VAT | £102 £2.04 each £85.00 ex VAT | £279 £5.58 each £232.50 ex VAT |
| 100 | £65 65p each £54.17 ex VAT | £37 37p each £30.83 ex VAT | £152 £1.52 each £126.67 ex VAT | £329 £3.29 each £274.17 ex VAT |
These prices are read from our live price list each time this page loads, so they match the posters page. Select a price to open that option on the product page.
Posters are dispatched 5 to 8 working days after you approve your artwork, and mainland delivery usually takes a further 1 to 2 working days. See our delivery page for areas we quote separately.
Setting up an A3 poster
- Page size: 303 x 426mm, the A3 size plus 3mm of bleed on every edge. Our guide to what bleed is explains why.
- Safe area: keep text and logos at least 10mm inside the trim.
- Images: aim for 300dpi at full size, 3508 x 4961 pixels for a photo filling the poster. A3 is often read up close, so the extra detail shows. See our glossary entry on dpi.
- File: a PDF in CMYK, with fonts embedded or outlined. Our CMYK vs RGB guide explains the colour change from screen to print.
Our free poster templates include A3 at 303 x 426mm, with trim and safe area marked, as a PDF and an SVG. In Canva, set a custom size of 303 x 426mm; our Canva to print guide has the steps. The artwork guidelines list every check.
Is my photo big enough for A3?
Divide the long side in pixels by 16.54, the long side of A3 in inches. A 4000 x 3000 pixel phone or camera photo gives 4000 ÷ 16.54 = 242dpi, which looks sharp at A3.
Proof and VAT
When you upload, a free automatic check looks at size, bleed, colour mode, resolution and fonts, and you approve an on-screen proof before you pay. Add a manual proof in your basket if you want a person to check your file; see proofs and file checks.
Posters are standard-rated for VAT, so A3 prices include VAT at 20%. Our VAT on printing page explains why posters are treated differently from leaflets.
Questions
What size is an A3 poster? An A3 poster is 297 x 420mm, which is 29.7 x 42cm or about 11.7 x 16.5 inches. With 3mm of bleed on every edge, the artwork is 303 x 426mm.
Is A3 twice the size of A4? Yes. A3 (297 x 420mm) is two A4 sheets (210 x 297mm) side by side. An A4 design scales up to A3 at 141% without cropping, because every A size has the same proportions.
How much does it cost to print an A3 poster? One A3 poster on 170gsm silk costs £16 including VAT, and 10 cost £25, which is £2.50 each. Delivery to UK mainland addresses is free.
Can I order just one A3 poster? Yes. Posters start from a single copy per design, and you can also order 5, 10, 25 or 50, or 100 on our standard 170gsm silk. The price per poster falls as the quantity rises.
What resolution does an A3 poster need? 300dpi at full size is best, which is 3508 x 4961 pixels for the finished poster or 3579 x 5031 pixels with bleed. 150dpi, 1754 x 2480 pixels, is the least that looks sharp from a few steps away.
What paper are A3 posters printed on? 170gsm silk as standard, printed on one side in full colour. Silk has a soft sheen with less glare than gloss, and it is for indoor display. You can also choose other silk and gloss weights, 150gsm satin, or an outdoor paper: 115gsm blueback or 170gsm waterproof PVC.
Do you print A3 posters double-sided? No. Our posters are printed on one side only. For a double-sided A4 or smaller handout, see our leaflets.
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