August 25, 2026
A B1 poster measures 707 x 1000 mm, or about 27.8 x 39.4 inches. It is an ISO B-series format used mainly in European and Asian markets for large promotional posters. Here is everything you need to know about the B1 size.
The B1 poster size is part of the ISO B-series paper standard, an international format system used alongside the more widely known A-series. B-series sizes are intermediate between A-series sizes, which means B1 falls between A1 and A0 in terms of physical area. It is a large poster format, well-suited for high-visibility outdoor advertising and major promotional campaigns.
Most of our campaign work uses US standard sizes measured in inches, because the United States does not use the ISO paper standards. But we frequently encounter B-series specifications when coordinating with international print partners, or when clients request specific European market poster formats. Understanding the B1 size and where it fits in the global poster format environment is useful for anyone working across international markets.
This guide covers the B1 poster size in detail: exact dimensions, use cases, how it compares to both US and ISO A-series poster sizes, and what you need to know for print production at this size.
The B1 poster size has the following dimensions:
In portrait orientation, B1 is 707 mm wide and 1000 mm tall. In environment orientation, those measurements swap: 1000 mm wide by 707 mm tall.
The aspect ratio of B1 is the same as all other ISO B-series sizes: 1:1.414 (the square root of 2). This is the defining characteristic of the ISO paper standard. Every B-series size shares this ratio, making scaling from one B size to another proportionally consistent.
B1 Quick Reference
Width: 707 mm / 70.7 cm / 27.83 in. Height: 1000 mm / 100.0 cm / 39.37 in. At 150 DPI (suitable for outdoor viewing at 10+ feet), the file dimensions are 4,175 x 5,906 pixels. At 300 DPI, the file dimensions are 8,350 x 11,811 pixels. File at 300 DPI in CMYK: approximately 375 MB uncompressed TIFF.
| Size | Width (mm) | Height (mm) | Width (inches) | Height (inches) |
|---|---|---|---|---|
| B5 | 176 | 250 | 6.93 | 9.84 |
| B4 | 250 | 353 | 9.84 | 13.90 |
| B3 | 353 | 500 | 13.90 | 19.69 |
| B2 | 500 | 707 | 19.69 | 27.83 |
| B1 | 707 | 1000 | 27.83 | 39.37 |
| B0 | 1000 | 1414 | 39.37 | 55.67 |
The B1 poster does not correspond exactly to any standard US poster size. The closest US format is the cinema one-sheet at 27×40 inches (685.8 x 1016 mm). The B1 at 707 x 1000 mm is slightly wider and slightly shorter than the US one-sheet, but the two are very close in physical area.
| Format | Width (inches) | Height (inches) | Area (sq in) |
|---|---|---|---|
| ISO B1 | 27.83 | 39.37 | 1,096 |
| US One-Sheet (27×40) | 27 | 40 | 1,080 |
| US 24×36 | 24 | 36 | 864 |
| ISO A1 | 23.39 | 33.11 | 775 |
| US 40×60 | 40 | 60 | 2,400 |
The B1 is notably larger than the A1 (775 sq in vs. 1,096 sq in). If you are moving between A-series and B-series formats, the size jump is significant. An A1 design scaled to B1 fits comfortably because B1 is larger, but the proportions change because the aspect ratio is the same. The design looks similar but the poster is physically much larger.
B1 posters appear most commonly in the following contexts:
In several European countries, the B1 format is a standard for outdoor promotional posters. Germany, Austria, Switzerland, and some other Central European markets use B-series sizes in their outdoor advertising infrastructure. Street-level display cases, transit stop poster frames, and commercial display boards in these markets are often built to B-series specifications.
If you are planning a campaign in Europe, confirm which standard the outdoor display hardware uses in your target city. Major cities like London, Paris, and Amsterdam have display hardware from multiple vendors with different size specifications. Do not assume B1 is universal across all European markets.
Japan uses both ISO A-series and B-series sizes. The Japanese B-series (JIS B standard) actually differs slightly from the ISO B-series in some sizes, though the B1 dimensions are the same. The B1 format is a common large-format promotional poster size in Japanese retail and entertainment advertising.
Some European film markets use B1 for theatrical poster display in cinema lobbies. This is the European counterpart to the US one-sheet. Frame systems in European cinemas are often built for B1 or A1 depending on the theater and the distributor’s regional preferences.
Museum and gallery exhibition posters often use B1 in European markets. The format is large enough to display artwork effectively and readable from the viewing distances common in museum lobbies and gallery corridors. Art print publishers selling in European markets also use B1 as a primary large-format print size.
Producing B1 posters requires wide-format print equipment. A B1 poster at 707 mm (27.83 inches) wide requires a printer with at least a 28-inch (or 70 cm) wide print head. Most professional wide-format inkjet printers with 36-inch or wider roll stock can produce B1 without waste on the width.
For file setup, here are the specs you need:
At 150 DPI, the B1 print file is 4,175 x 5,906 pixels. This is an appropriate resolution for a poster viewed from more than 10 feet. At 300 DPI for close-range display, the file is 8,350 x 11,811 pixels, which creates a large but manageable print file.
US Print Shops and the B1 Format
Most US commercial print shops do not stock paper or calibrate equipment specifically for B-series sizes. If you need B1 posters printed in the US, specify the dimensions in millimeters and inches and confirm the shop can produce a custom size. They likely can, but it will be a custom order priced accordingly. For B1 production at scale, working with a European print partner is usually more cost-efficient.
Designing for B1 effectively means thinking about how the poster will be viewed at its actual installed size. At nearly a meter tall and over 70 centimeters wide, B1 is a large physical presence. Text that looks readable on a computer monitor can look small when the poster is installed at street level and viewed from a typical pedestrian distance of 3 to 5 meters.
Headline text on a B1 poster for street-level display should be no smaller than 80 to 100 points. That translates to roughly 28 to 35 mm in physical height on the printed piece. At a 3-meter viewing distance, this produces text that reads easily without the viewer needing to stop and look closely. Supporting body text can be slightly smaller, but avoid using type below 40 points on a B1 poster that will be read from walking distance.
High-contrast color combinations read better at distance. Black text on a bright or light background, or white text reversed out of a strong color, maintain legibility across the typical viewing conditions for a street-level B1 installation. Low-contrast combinations that look elegant in a PDF proof often become difficult to read when viewed at an angle or in variable outdoor light conditions.
Keep the central visual hierarchy simple. B1’s large format allows for generous imagery and bold graphic elements, but a poster trying to communicate five different messages at B1 scale does not read better than one trying to communicate five messages at A3. The poster communicates one message well or competes with itself for the viewer’s attention. Design for the one message. Let the format amplify it.
The choice between B1 and A1 depends on your target market and what the display infrastructure in that market supports. Here is a direct comparison.
A1 is the more widely used format globally. It is the primary large-format outdoor poster size in most international markets outside the US. A1 is 594 x 841 mm (23.4 x 33.1 inches). It is smaller than B1 and fits within display hardware built for the A-series standard.
B1 is larger than A1 by a factor of approximately 1.41. It delivers more visual presence on a wall but requires display hardware and frame systems built for B-series sizes. In markets where B-series is the standard, B1 is the correct choice for large-format display. In markets where A-series is the standard, A1 is the correct choice.
When working in an unfamiliar international market, always research the local poster display standard before committing to a size. Getting this wrong means printing posters that do not fit the available display hardware.
We rarely use B1 format in our US domestic campaign work. The US market runs on inch-based standard sizes, and our print partners are set up for those standards. When a client requests B1 for a specific international campaign component, we specify it in both mm and inches to ensure clarity with all parties involved in production.
The nearest US equivalent for the scale and visual impact of a B1 poster is the 27×40 one-sheet or a custom 28×40 if the client wants to approximate B1 dimensions on US equipment. Either way, it is a large format that commands attention at street level or in a transit environment.
For clients who want the high-impact presence of a large outdoor format in US markets, we typically recommend 24×36 for standard production and 40×60 for maximum impact. Both are within US standard sizes, are efficiently produced on US equipment, and deliver the visual presence of a B1 or larger format at locations with appropriate viewing distances.
The B1 poster size becomes most relevant when campaigns cross national borders or when clients want to produce materials that will be used in both the US and European markets. Here is how to think about B1 in an international campaign context.
The UK uses ISO B-series sizing more commonly than the US. B1 appears in UK cinema lobbies, major retail environments, and some outdoor advertising applications. Brands running US-and-UK simultaneous campaigns sometimes need to produce both a 24×36 version for US placements and a B1 version for UK placements. The dimensions are close enough that artwork can usually be adapted with minor adjustments rather than a complete redesign, but the difference in aspect ratio (B1 is slightly taller relative to width than 24×36) means images can get cropped if artwork is simply resized without review.
Music tours, film releases, and brand launches that cross from the US into European markets encounter B1 in Germany, France, the Netherlands, and Scandinavian countries where the ISO B-series is standard in the entertainment and events poster market. Touring bands and film distributors that want consistent visual presentation across US and European markets need to produce both 24×36 US format and B1 European format to fit the display hardware in each market.
In the US, B1 is not a standard format and most print vendors do not stock paper at this exact dimension. Using B1 in the US requires a custom print order with longer lead times and a price premium. The only situations where B1 makes sense for a US-market campaign is when the client specifically wants the European format for aesthetic reasons, or when the installation surface dimensions happen to make B1 a better fit than either 24×36 or 27×40. In practice, US campaigns should default to 24×36 or 27×40 and use B1 only for international components of the same campaign.
Designing a B1 poster file for US print vendors requires converting the metric dimensions to inches: 27.83 inches wide by 39.37 inches tall. Set the document at this dimension in your design application (InDesign, Illustrator, or Photoshop) at 300 DPI for print quality. Add at least 0.125 inches of bleed on all sides. Deliver the file as a press-quality PDF. When ordering, specify B1 or provide the exact inch dimensions, because most US print vendors will not recognize the B1 designation without clarification.
A B1 poster is approximately 27.83 inches wide by 39.37 inches tall. In metric, it is 707 mm wide by 1000 mm tall (70.7 cm x 100 cm). This is a large-format poster size used primarily in European and Asian markets.
Yes. B1 (707 x 1000 mm) is larger than A1 (594 x 841 mm). B1 has an area of approximately 707,000 mm², while A1 has an area of approximately 500,000 mm². B1 is about 41% larger in surface area than A1.
B1 is rarely used in the United States. US poster campaigns use inch-based standard sizes. The B-series ISO standard is not part of the US commercial printing system. If you need a B1 poster in the US, it will be a custom order at most print shops and may cost more than standard US sizes.
The closest US poster size to B1 is the 27×40 inch cinema one-sheet. It is slightly narrower and slightly taller than B1 but very close in total area. For outdoor campaigns where a B1-equivalent impact is needed in the US, we would recommend a custom 28×40 inch format or a standard 24×36 or 40×60, depending on the specific application.
For close-range indoor display, design at 300 DPI. At 300 DPI, a B1 file is 8,350 x 11,811 pixels. For outdoor display at viewing distances of 10 feet or more, 150 DPI is acceptable, giving you a 4,175 x 5,906 pixel file. Always confirm resolution requirements with your print shop.
In Adobe Illustrator, set your document size to 707 mm x 1000 mm with a 3-5 mm bleed on all sides. Set the color mode to CMYK for print. In Photoshop, set document dimensions to 707 mm x 1000 mm with 300 DPI (or 150 DPI for large-format outdoor) in CMYK color mode. Export as PDF or TIFF for print submission.
For more on this, explore our guerrilla marketing services.
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For more on this, explore our street team activations.
Some US print shops with wide-format inkjet capability can produce B1 as a custom size. The equipment needs to be at least 28 inches wide to print B1 without cutting. Most professional print shops with 36-inch or 44-inch wide printers can accommodate B1 dimensions. Call ahead and specify the exact dimensions in both millimeters and inches.
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