Poster Size List: A0 to B3 Dimensions and How to Choose by Use, Viewing Distance and Resolution

In Japan, poster sizes are usually chosen from two series, A and B. Both have dimensions fixed by standards.

The eight most commonly used are A0 to A3 and B0 to B3. Which one fits depends on where you put it up and where people see it from.

Here is the key point. If you work backward from the viewing distance, you can narrow the poster size down to one.

This article covers the following:

• Dimensions of A0 to A3 and B0 to B3 (mm, cm, pixels)
• How to choose by use (shop, station, event, room, conference)
• Viewing distance and a guide to text size
• What dpi large-format print data needs
• How poster size relates to frame size
• How to print large on a home printer (tiled printing)
• Common mistakes

Dimensions are shown in tables based on the standards (ISO 216, JIS P 0138).

Conclusion: What are the poster sizes?

Source: JIS P 0138, ISO 216, ANSI/ASME Y14.1

Dimensions in the table are given as "width × height" in portrait orientation. px is the pixel count when printing at 300dpi.

As the table shows, each step down in number doubles the area. For the same number, B size is larger than A size.

If you are unsure, choose as follows:

• Inside a shop or on a notice board: A2, B2, A1
• Seen from a distance at a station or in a corridor: B1, B0 (follow the rules of the venue)
• Event or trade show booth: A1, B1
• Decorating a room: A3 to A1, B2 (decide together with the frame size)
• Conference presentation: the size specified in the guidelines

A list that includes other paper sizes is in Paper Size List.

How do you check poster sizes with the calculator tool?

Choose a paper size and dpi in the tool above to see the pixel count for that poster size. The same tool also gives the scale for enlarging or reducing.

The tool runs only in your browser. The values you enter are not sent anywhere.

How do A and B poster sizes differ?

The A series is the international standard (ISO 216), and the B series is the Japanese JIS series. For the same number, B size is a step larger.

As the figure shows, cutting A0 in half gives A1, and halving again gives A2. A0 is defined so that its area is almost exactly 1 square meter.

The B series works the same way. B0 has an area of almost 1.5 square meters.

Both A and B sizes have the same short side to long side ratio of 1 : √2. So data made at A4 can be enlarged straight to B2.

One thing to watch: B size dimensions differ between Japan and other countries. The B sizes in the table are the JIS values.

If you choose "B2" at an overseas printing service, you may get the ISO B size (slightly smaller).

How do you choose a poster size by use?

Choose a poster size by the size of the place where it goes and the distance to the viewer. Guidelines by use are in the table below.

The "common sizes" in the table are general trends. Where there is a specification, it always comes first.

Are poster sizes fixed for stations?

Yes. Each railway company sets the sizes for station posters.

For example, Kintetsu station posters are B2. Smaller posters are mounted on a backing board to make them B2.

There is also a rule to leave a 10mm "covered margin" from the top, bottom, left and right edges. This is because the notice board frame hides the edges of the paper.

How do you decide a conference poster size?

Make a conference poster at the size given in the conference guidelines. It is given as a paper name such as A0, or as the panel width and height.

Also check the guidelines for portrait or landscape. If only the panel dimensions are given, compare them with the mm in the table and pick a size that fits.

What size poster should you hang in a room?

For a poster to hang in a room, decide by the outer size once it is framed. This is because the frame is a step larger than the paper.

How do you decide poster size from the viewing distance?

A guide for viewing distance is about twice the length of the poster's diagonal. This guide comes from Canon's printing course.

Calculated for B2, it works out as follows:

• Diagonal: √(515² + 728²) ≈ 892mm
• Viewing distance: 892mm × 2 ≈ 1.8m

The values for the other sizes, worked out with the same formula, are in the table below.

The table also works in reverse. If you want the whole poster visible from 3m away, choose A0 or B0.

If you want it seen from the street in front of a shop, measure the distance from the street to where it will hang before choosing.

How do you set poster text size from the distance?

Text size on a poster depends on the distance to the reader. Guidelines from Japan's Ministry of Land, Infrastructure, Transport and Tourism give a guide for each distance.

They are meant for signs in stations and similar places, but they also work for poster text.

"Guide in points" is the Japanese text height converted to pt. It was calculated with 1pt = 25.4 ÷ 72 ≈ 0.353mm.

Japanese characters look a little smaller than the box set by the pt size. The table values are minimums, so going a little larger is safer.

The guidelines treat the table values as the minimum. They also say that people with poor eyesight need even larger text.

Splitting text into two levels makes it easier to decide:

• Title: the distance at which people notice it from afar (57pt or more for 4 to 5m)
• Body text: the distance at which people come close to read (26pt or more for 1 to 2m)

What dpi suits each poster size?

Large posters are seen from a distance, so 150 to 200dpi is often enough. If people will read them up close, use 300dpi.

dpi is the number of dots in 1 inch (25.4mm). See A4 Size Pixel Count for details.

The manufacturers' guidelines are as follows:

• Canon: A4 and smaller look lacking below 300ppi. A2 looks sharp enough even at 200ppi
• HP: posters need 150 to 300dpi at the finished size. A2 and A1 need 200 to 300dpi
• Epson: recommends 300 to 360dpi. However, the detail needed changes with viewing conditions

This article applies these to the viewing distance and uses the guides below.

Pixel counts at 150dpi and 350dpi are in the table below.

Source: JIS P 0138, ISO 216, ANSI/ASME Y14.1

Why is 150dpi enough for large formats?

Because when the viewing distance doubles, half the dpi looks equally fine.

In Canon's guide, A4 is 300ppi and A2 is 200ppi. A2 is seen from farther away than A4, so a lower value looks the same.

Applying this relationship to sizes larger than A1 gives about 150dpi.

However, posters read up close, such as at conferences, are different. If people look up close, use 300dpi even for A0 (HP's guideline).

What goes wrong if you make it at 300dpi?

An A0 at 300dpi makes a very heavy file. Your computer and software slow down.

Making A0 at 300dpi works out as follows:

• 9933 × 14043 ≈ 139.49 million pixels
• Multiply by the color data (3 bytes per pixel) and it is about 418MB before compression

At 150dpi, it is about 34.88 million pixels, or about 105MB. Halving the dpi cuts the data to a quarter.

Can you make a poster from a smartphone photo?

Yes. Up to about B2, a smartphone photo works.

A 12-megapixel photo is about 4000px on the long side. Fitted to the long side of B2, that gives about 140dpi.

• 12 megapixels: 4000 ÷ 28.66 inches ≈ 140dpi
• 48 megapixels: 8000 ÷ 28.66 inches ≈ 280dpi

If you will print photos small and hand them out, the L-size photo article helps.

How does poster size relate to frames?

Choose a frame by the paper size it holds, such as "for A2" or "for B2". Measure the wall space by the outer size of the frame.

Frames have the following three dimensions:

In a frame with a mat, the window is smaller than the paper and hides its edges. Do not put text or logos at the edges.

"73 52", a common search, is B2 in cm, rounded. You can confirm it in the cm column of the table. Frame and poster shops sometimes list sizes in cm.

Frames such as "60 90" or "40 50" have a different ratio from A and B sizes. This is because they are made in round cm numbers.

An A or B size poster in one of these frames will either leave a gap or have its edges hidden.

How do you print a poster size on a home printer?

A home printer can make a poster with "poster printing (tiled printing)", which joins several A4 sheets together.

Folding an A size in half gives the next number, so laying A4 sheets side by side gives A sizes.

Because of the overlap (the glue margin) and the unprintable border at the paper edge, the finished poster is slightly smaller than in the table. 3 × 3 is not a standard size, so store-bought frames will not fit.

The main places to set it are as follows:

• Canon: in the printer driver, go to [Basic Settings] > [Page Layout] and choose [Poster (2 × 2)] or similar. You can also add an overlap margin and cut lines
• Epson: in the Windows driver, set it from "Multi-Page/Poster" or similar. On some models it cannot be chosen if borderless is checked
• Adobe Acrobat: in the print dialog, choose "Poster" under "Page Sizing & Handling". You can set the scale, overlap, tile marks and labels

Acrobat lets you set any scale. To go from A4 to A1, the scale is about 283%. That is √2 multiplied three times (≈ 2.83).

What are common poster size mistakes?

The most common are the B size dimension difference and too little resolution. The mistakes people ask about most are in the table below.

Comparing the finished size and dpi with the tables before printing prevents these. The formula for bleed is in the A4 Size Pixel Count article.

What terms come up with poster sizes?

What else should you know about poster sizes?

What scale do you use to enlarge A4 data to a poster?

A4 to A3 is about 141%, to A2 is 200%, and to A1 is about 283%. Each step up multiplies by √2 (about 1.41).

From an A size to the B size with the same number is about 122%. A and B sizes share the same ratio, so enlarging doesn't cut off the edges. The calculator tool above also gives the scale.

Does the method change between portrait and landscape?

No. You just swap the width and height.

The values in the tables are for portrait.

For landscape, make the data in landscape from the start. If you make it in portrait and rotate it, some software will shrink it.

What poster sizes are used overseas?

In the US, posters in round inch numbers are common. Their ratio is not 1 : √2, so they don't fit A or B size frames.

If you use an overseas frame, make the poster to the same standard. The difference from US paper sizes is explained in Letter vs A4.

Frequently Asked Questions About Poster Sizes

What are the common poster sizes?

Indoors, A2, A1 and B2 are common. At stations and similar places, B1 and B0 are common.

If the place has a specification, follow it. The dimensions are in the list above.

What size is a "73 52" poster?

B2. It is the B2 dimensions in cm, rounded to whole numbers.

Find the B2 row in the cm column of the table to confirm.

Which is bigger, A1 or B2?

A1. A1 has about 1.33 times the area of B2.

Between A2 and B2, B2 is about 1.5 times A2. You can compare them in mm in the table.

What dpi should a poster be?

For A1 and larger seen from a distance, 150 to 200dpi. For close viewing, 300dpi is the guide.

If the print shop specifies a value, use that.

Can you make an A1 poster on a home printer?

Yes. Joining eight A4 sheets gives the size of A1.

Printer tiling is usually 2 × 2 or 4 × 4. To make A1 from eight sheets, set the scale to about 283% in the "Poster" option of Acrobat.

Is a "60 90" poster A size or B size?

No. It is a size in round cm numbers, neither A size nor B size.

Its ratio is different, so it doesn't fit A or B size frames.

What else should you read about poster sizes?

Sources

• ISO 216:2007 Writing paper and certain classes of printed matter. Trimmed sizes. A and B series (ISO)
• JIS P 0138 Finished Sizes of Processed Paper (Japanese Industrial Standards Committee, JIS Search)
• Print Course That Changes Your Photos, Lesson 3: Pixel Count and Resolution (Canon)
• What is the best image resolution for printing posters? (HP Large Format)
• Printing and scanning images: What is the recommended resolution for output print size? (Epson UK FAQ KA-01467)
• Barrier-Free Guidelines for Public Transport Passenger Facilities, Passenger Facilities Edition, 2. Guidelines for Guidance and Signage (Ministry of Land, Infrastructure, Transport and Tourism)
• Put Your Poster Up in Our Stations (Kintetsu Railway)
• Poster Printing (Canon Online Manual)
• How Do I Set Up Poster Printing? <Windows> (Epson FAQ 35874)
• Printing Large-Format Documents as Posters in Acrobat (Adobe)