Poster Size in CM: Complete Metric Dimensions Guide

Whether you are working with a European printer, setting up a file in metric units, or simply want to know how big a poster really is in physical terms, centimeter measurements give you a clear picture. This guide covers every standard poster size in centimeters, including both U.S. standard sizes converted to metric and the international ISO sizes used in Europe and most of the world.

We handle print projects across the U.S. and internationally. Getting the unit conversion right before you print is essential. Here is everything you need.

Key Poster Sizes in CM
18 x 24 in = 45.7 x 61 cm. 24 x 36 in = 61 x 91.4 cm. 27 x 40 in = 68.6 x 101.6 cm. 36 x 48 in = 91.4 x 121.9 cm. A1 (ISO) = 59.4 x 84.1 cm. A0 (ISO) = 84.1 x 118.9 cm.

U.S. Poster Sizes in Centimeters

U.S. poster sizes are defined in inches. Here are all standard U.S. poster sizes converted to centimeters. To convert inches to centimeters, multiply by 2.54.

International Poster Sizes in Centimeters (ISO Series)

The ISO paper system uses precise metric dimensions. Each size in the A-series is exactly half the area of the next larger size. These are the poster sizes used in Europe, Australia, Canada, and most countries outside North America.

How to Convert Poster Sizes Between Inches and Centimeters

The conversion formula is simple and exact:

• Inches to centimeters: multiply by 2.54
• Centimeters to inches: multiply by 0.3937 (or divide by 2.54)

Here are the most common conversions you will need:

• 24 in = 60.96 cm (rounded to 61 cm)
• 36 in = 91.44 cm (rounded to 91.4 cm)
• 18 in = 45.72 cm (rounded to 45.7 cm)
• 48 in = 121.92 cm (rounded to 121.9 cm)
• 27 in = 68.58 cm (rounded to 68.6 cm)
• 40 in = 101.6 cm (exact)

Ordering from International Printers
If you are ordering from a European or Canadian print shop, they will often ask for dimensions in millimeters (mm), not centimeters. To convert: multiply inches by 25.4. A 24 x 36 in poster is 609.6 x 914.4 mm. Give the print shop the millimeter value for precision.

Poster Size in CM: The Most Common Formats

Here is a detailed breakdown of the most frequently used poster sizes in centimeter measurements.

45.7 x 61 cm (18 x 24 inches)

The small poster standard in the U.S., roughly equivalent to an international A2 (42 x 59.4 cm) though slightly larger. Used for concert posters, retail displays, and event advertising. Fits standard poster tubes and display frames.

61 x 91.4 cm (24 x 36 inches)

The general-purpose large poster. This is the most commonly purchased size in the United States for consumer wall posters and advertising. The metric equivalent in Europe is A1 (59.4 x 84.1 cm), which is slightly smaller. If you are ordering a 24 x 36 poster from a European shop, confirm they can produce the U.S. size rather than defaulting to A1.

68.6 x 101.6 cm (27 x 40 inches)

The movie one-sheet. No standard ISO size is equivalent to this format. Its dimensions derive from the specific display hardware standards of American multiplexes, not from any mathematical paper size system.

91.4 x 121.9 cm (36 x 48 inches)

The conference and trade show standard. The ISO equivalent is A0 (84.1 x 118.9 cm), which is slightly smaller. If you are presenting at a U.S. conference that specifies 36 x 48, do not substitute A0. The difference is 7.3 cm in width and 3 cm in height, which may cause the poster to not fill the display board properly.

Working in Centimeters in Design Software

Most professional design applications (Adobe Illustrator, InDesign, Affinity Publisher) let you set document units to centimeters. Here is how to set up a document at common poster sizes in cm:

Adobe Illustrator / InDesign

File menu > New. Set Width and Height. Change the unit dropdown to Centimeters. Enter the dimensions. Confirm the bleed setting (add 0.317 cm or 3.17 mm on all sides for edge-to-edge designs).

Canva

Select “Custom Size” from the template selector. Change the unit from pixels to centimeters. Enter width and height. Canva works in centimeters natively for international users.

PowerPoint

Design tab > Slide Size > Custom Slide Size. Set width and height in centimeters. For a 24 x 36 inch poster in cm, enter 61 cm x 91.44 cm.

Poster Size in CM: Printing Considerations

Whether you submit your file in centimeters, inches, or millimeters, the actual print output is the same. The important thing is that the dimensions in your file match the requested print dimensions exactly.

When sending files to a printer:

• Confirm which unit system the printer uses (most U.S. shops use inches)
• Convert your cm dimensions to inches or mm before calling to confirm the order
• A PDF preserves all dimensions exactly as specified in the design file
• Never scale a PDF at the print stage. The file should be at 100% of the intended output size

What is the standard poster size in cm?

The most common U.S. poster size in cm is 61 x 91.4 cm (24 x 36 inches). The most common international poster size in cm is 59.4 x 84.1 cm (A1).

How big is a 24 x 36 inch poster in centimeters?

A 24 x 36 inch poster is approximately 61 x 91.4 centimeters (exactly 60.96 x 91.44 cm).

What is A1 poster size in cm?

A1 is 59.4 x 84.1 centimeters (594 x 841 mm). It is slightly smaller than the U.S. 24 x 36 inch standard.

What is A0 poster size in cm?

A0 is 84.1 x 118.9 centimeters (841 x 1189 mm). It is the closest international equivalent to the U.S. 36 x 48 inch conference poster format.

How do I convert poster size from inches to cm?

Multiply the inch measurement by 2.54. For a 24 x 36 inch poster: 24 x 2.54 = 60.96 cm wide, 36 x 2.54 = 91.44 cm tall.

Is an 18 x 24 inch poster the same as A2?

No. An 18 x 24 inch poster is 45.7 x 61 cm. A2 is 42 x 59.4 cm. The 18 x 24 is slightly larger than A2.

What cm size should I set for a conference poster?

If the conference specifies 36 x 48 inches, set your document to 91.4 x 121.9 cm (or 914 x 1219 mm). If the conference specifies A0, set it to 84.1 x 118.9 cm.

Can I print a poster designed in cm at a U.S. print shop?

Yes. Provide the dimensions in inches when you call to confirm the order. The print file itself can be in any unit; the physical output is the same.

What is a 60 x 90 cm poster in inches?

60 cm = 23.6 inches, 90 cm = 35.4 inches. A 60 x 90 cm poster is approximately 23.6 x 35.4 inches, which is close to but slightly smaller than the U.S. 24 x 36 inch standard.

What bleed should I add to a poster file in centimeters?

Add 0.317 cm (3.17 mm) on all sides. This is the centimeter equivalent of the standard 0.125-inch bleed used in U.S. print production.

Working with Centimeter Measurements in Print Production

Most U.S. commercial print shops use inches as their primary unit. Most international print shops use millimeters. Centimeters are commonly used in design software and specifications but are less common in print shop job orders.

When you provide dimensions to a U.S. print shop, convert your centimeter measurements to inches first. When providing dimensions to a European or Canadian print shop, convert to millimeters. This is a small step but prevents order errors caused by unit confusion.

Design software typically allows you to switch between units at any time without affecting the file dimensions. In Adobe Illustrator, you can change the ruler units under Preferences, Units. Switching from inches to centimeters does not resize the document; it only changes how the measurements are displayed. The physical dimensions remain the same regardless of the display unit.

Poster Sizes in CM for European and International Markets

If you are producing poster content for European markets, international events, or clients outside North America, the ISO A-series sizes are the relevant standard. Here is a practical guide to how these sizes compare to U.S. formats in centimeters.

A3 (29.7 x 42 cm) is the European equivalent of a small event poster. It is used in the same contexts as U.S. 11 x 17: local event promotion, restaurant specials, community announcements. Most European office printers print A3.

A2 (42 x 59.4 cm) is the European equivalent of the U.S. 18 x 24 poster. Concert promoters, gallery shows, and event advertising in Europe use A2 as a primary format. It is slightly smaller than the U.S. 18 x 24 but fits the same general display contexts.

A1 (59.4 x 84.1 cm) is the European general-purpose large poster. It plays the same role in European advertising that 24 x 36 plays in the U.S. Most European print shops, frame retailers, and display hardware suppliers have A1 as a standard offering.

A0 (84.1 x 118.9 cm) is the European academic conference poster size. It is slightly smaller than the U.S. 36 x 48 (91.4 x 121.9 cm) in both dimensions. If you are presenting at a European conference that specifies A0, do not substitute a U.S. 36 x 48. The size difference matters for display board compatibility.

Centimeter Measurements for Specific Design Applications

Some specific design applications benefit from working in centimeters rather than inches. Print design for European clients, package design that follows ISO standards, and signage for metric-primary environments all benefit from centimeter-native design files.

Setting up Illustrator or InDesign in centimeters is straightforward. In Illustrator, go to Edit, Preferences, Units and set General to Centimeters. In InDesign, go to InDesign, Preferences, Units and Increments and set Ruler Units to Centimeters. Both applications work equally well in any unit system; the choice is purely one of display convenience.

When designing for a U.S. print shop in centimeters, keep in mind that you will need to convert back to inches for the print order. The shop will ask “what size are you ordering?” and expects the answer in inches. Having the conversion ready (or using the formula: divide centimeters by 2.54 to get inches) makes the conversation smooth.

Frequently Confused Centimeter Dimensions

A few common poster sizes in centimeters are close enough to each other that they can be confused in ordering. Here are the pairs most often mixed up and how to distinguish them:

• A1 (59.4 x 84.1 cm) vs. U.S. 24 x 36 (61 x 91.4 cm): The U.S. format is 1.6 cm wider and 7.3 cm taller. Not interchangeable in frames or display hardware.
• A0 (84.1 x 118.9 cm) vs. U.S. 36 x 48 (91.4 x 121.9 cm): The U.S. format is 7.3 cm wider and 3 cm taller. Conference organizers who use U.S. standards want 91.4 x 121.9 cm, not 84.1 x 118.9 cm.
• A2 (42 x 59.4 cm) vs. U.S. 18 x 24 (45.7 x 61 cm): The U.S. format is 3.7 cm wider and 1.6 cm taller. Similar enough to display in the same context but not interchangeable in specific display frames.

When in doubt about which size a venue or organizer expects, ask for the dimensions in millimeters. Millimeters are unambiguous. There is no rounding confusion at this level of precision, and a dimension stated in millimeters translates directly to a design file specification without approximation.

Poster Size in CM for Academic and Research Applications

Academic researchers based in Europe, Australia, and most international institutions work in metric units and think in ISO paper sizes. If you are in this context and preparing a conference poster, here is what you need to know about the centimeter dimensions that apply to your work.

A0 (84.1 x 118.9 cm) is the standard for academic conference posters outside North America. This is the size specified by most European scientific conferences, international congresses, and research events organized under ISO conventions. If your conference is held in Europe or organized by a European institution, A0 is almost certainly the correct size.

If your conference is organized by a U.S. institution or held in North America, the standard shifts to 36 x 48 inches (91.4 x 121.9 cm). The size difference is noticeable: the U.S. format is 7.3 cm wider and 3 cm taller than A0. A poster designed for A0 will have visible margins at the sides and top when mounted on a board sized for 36 x 48. A poster designed for 36 x 48 will overhang an A0 board by 7.3 cm in width.

Always confirm the expected format with the conference organizer before setting up your design file. Do not assume either A0 or 36 x 48 without checking. The question is simple and the organizer will have a clear answer. The cost of printing the wrong size is much higher than the cost of a brief email to confirm.

Design Software Centimeter Settings for Common Poster Sizes

If you prefer to work in centimeters in your design software, here are the document setup values for the most common poster sizes.

• For a 24 x 36 inch poster: Set document to 60.96 cm wide x 91.44 cm tall (or round to 61 x 91.4 cm for convenience)
• For a 36 x 48 inch poster: Set document to 91.44 cm wide x 121.92 cm tall (or round to 91.4 x 121.9 cm)
• For an 18 x 24 inch poster: Set document to 45.72 cm wide x 60.96 cm tall (or round to 45.7 x 61 cm)
• For an A1 poster: Set document to exactly 59.4 cm wide x 84.1 cm tall
• For an A0 poster: Set document to exactly 84.1 cm wide x 118.9 cm tall

Add bleed in centimeters: 0.317 cm on all sides (equivalent to 0.125 inches). Round to 0.32 cm for convenience in software that limits decimal places.

Practical Centimeter Reference Card

Here is a condensed centimeter reference for the poster sizes you will use most often in print projects. These are the dimensions that come up in conversations with European print shops, international conference organizers, and metric-native design teams.

When a European organizer says your poster board is 100 x 140 cm, that is close to B0 (100 x 141.4 cm). When they say 84 x 119 cm, that is A0. When they say 60 x 84 cm, that is A1. When a U.S. organizer says the board is 36 x 48 inches, that is 91.4 x 121.9 cm. When a frame at a retail store says 24 x 36 inches, that is 61 x 91.4 cm.

Knowing these conversions from memory speeds up every decision in a poster project that involves metric dimensions. The math is simple: multiply inches by 2.54 to get centimeters, multiply centimeters by 0.394 to get inches. After you do this calculation a few times, the most common conversions become second nature: 24 inches is 61 cm, 36 inches is 91 cm, 48 inches is 122 cm. Those three conversions cover most of the standard poster sizes you will encounter in your work.

Centimeter Dimensions and Print Quality

Working in centimeters does not change the quality requirements for poster printing. Resolution, color mode, bleed, and safety zone requirements are the same regardless of whether your file dimensions are specified in inches, centimeters, or millimeters. The physical output is determined by the physical dimensions and the print resolution, not by the unit system used in the file setup.

A 61 x 91.4 cm poster at 150 DPI is identical in physical output to a 24 x 36 inch poster at 150 DPI. The only difference is how the dimension is labeled in the file and in the print order. The printer does not know or care what unit system you used in your design software. What matters is that the physical dimensions of the final output are correct and the ink density is appropriate for the medium.

Final Note on Centimeter Precision

When working in centimeters, round to one decimal place for dimensions you communicate verbally or in writing (61 cm, 91.4 cm, 84.1 cm). Use full precision in design software when setting up files (60.96 cm, 91.44 cm). The rounding in verbal communication is fine for ordering and specification. The full precision in software ensures no rounding errors accumulate when converting back to inches for print production. This small discipline eliminates a source of dimensional ambiguity that can affect physical print output quality at the margins of standard sizes.

Any centimeter dimension you need that is not covered in this guide can be calculated in seconds: multiply the inch measurement by 2.54. The answer is exact. No approximation is involved. Metric and imperial measurement systems are defined in terms of each other with full mathematical precision, which means every conversion you need for poster sizing work is completely reliable when calculated correctly.

Frequently Asked Questions