Paper size is tied to both the design and the purpose of a printed piece, so you should lock in your size before you start designing. Skip that step and you will burn a lot of time resizing a finished layout. What are the standard paper sizes, the common poster sizes, the magazine and book sizes, and the card and postcard sizes? This guide walks through the paper sizes behind every common print product.

Every table below lists two figures: the trimmed size (the finished size after cutting) and the size with bleed. The bleed size adds the standard margin around the trim, so any colour or image that runs to the edge stays edge-to-edge with no white slivers after the sheet is cut.

A-series paper sizes

A4, A5 and A6 need no introduction — these are the sizes we handle every day. The A series is built on a sheet with a width-to-length ratio of 1 : √2 and an area of exactly one square metre (m²). That gives a largest size measuring 841 mm by 1189 mm (a √2 : 1 ratio), which is called A0. A1 is half of A0, A2 is half of A1, and so on.

So every A size keeps the same √2 : 1 ratio. When the standard was set, dimensions were fixed to whole numbers, so any halved size that lands on a fraction (under 1 mm) is rounded up.

A4 is the size you reach for most often, at 210 mm × 297 mm. The table below collects the A-series sizes, and because your design needs bleed too, it includes the bleed size for each.

SizeTrimmed sizeSize with bleed
A1594 × 841 mm600 × 847 mm
A2420 × 594 mm426 × 600 mm
A3297 × 420 mm303 × 426 mm
A4210 × 297 mm216 × 303 mm
A5148 × 210 mm154 × 216 mm
A6105 × 148 mm111 × 154 mm

B-series paper sizes

The B series and its numbering are less widely known. It is built on a sheet whose width edge is 1 metre and whose area is √2 square metres (m²). That gives a largest size measuring 1000 mm by 1414 mm (a 1 : √2 ratio), named B0. Halve that B0 sheet across its long edge and you get two B1 sheets, each 707 mm by 1000 mm; carry on the same way for B2, B3, B4 and beyond.

Compared with the A series, each B size has √2 times the area of the same-numbered A size — a B4 sheet, for example, is √2 times the area of an A4.

SizeTrimmed sizeSize with bleed
B1707 × 1,000 mm714 × 1,006 mm
B2514 × 728 mm520 × 734 mm
B3364 × 514 mm370 × 520 mm
B4257 × 364 mm264 × 370 mm
B5182 × 257 mm188 × 264 mm
B6148 × 105 mm134 × 188 mm

C-series paper sizes (envelopes made for the A series)

The C series shares the same √2 : 1 ratio as the A and B series. Each C size is set as the geometric mean of the matching A and B sizes.

C4, for instance, is the geometric mean of A4 and B4, still at a √2 : 1 ratio, so it sits between A4 and B4 in size. That is exactly what makes the C series the right envelope for A-series sheets — and, in turn, the B series the right envelope for C-series sheets.

SizeTrimmed sizeSize with bleed
C1648 × 917 mm654 × 913 mm
C2458 × 648 mm464 × 654 mm
C3324 × 458 mm330 × 464 mm
C4229 × 324 mm235 × 330 mm
C5162 × 229 mm168 × 235 mm
C6114 × 162 mm120 × 168 mm

Postcard sizes

The most common postcard size is 4R — the same size we use for printed photos. Because most postcards feature scenery and landmarks, the 4R photo size is what you see most. Postcard sizing is fairly free-form, though: A6, A5, 4R and 5R are all common choices.

SizeTrimmed sizeSize with bleed
4R (4 × 6 in)100 × 148 mm106 × 154 mm
5R (5 × 7 in)127 × 178 mm133 × 184 mm
A6148 × 105 mm154 × 111 mm
A5210 × 148 mm216 × 154 mm

Business card sizes

90 × 54 mm is the size anyone who has printed cards will recognise — it is what we use most in Hong Kong and Macau. Precisely because it is so common, it gives the recipient no visual surprise, so it is worth looking at the card sizes other countries use. Lately, as overseas online platforms have taken off, 85 mm × 55 mm has come into wider use as well. There is no single fixed card size — but do note that different sizes can carry different printing costs, so it pays to check before you settle on your dimensions.

SizeTrimmed sizeSize with bleed
Standard card
(used in China, Hong Kong, Macau, Taiwan, Singapore)
90 × 54 mm96 × 60 mm
Japanese card91 × 55 mm97 × 61 mm
European card85 × 55 mm91 × 61 mm
South American card90 × 50 mm96 × 56 mm

Other common sizes

Most print products are derived from the A, B and C paper sizes above, so we hope these tables give your design work a solid head start. If there are other print-product sizes you would like us to cover, get in touch — we will answer your questions and fold the answers into this article.

For more on sizing, see these related reads:

Not sure which size fits your project? WhatsApp us at +852 3001 5678 (English is fine) and we will help you pick the right size and bleed, with delivery across Hong Kong and Macau.