Poster Size in Centimeters: Every Standard Format Converted

US poster sizes in centimeters, ISO poster sizes in centimeters, and everything in between. A complete reference from a team that works with print vendors across multiple measurement systems.

Working across markets means working across measurement systems. US print shops quote in inches. European suppliers work in millimeters or centimeters. Many design programs let you work in either system, and knowing the centimeter equivalents for every common poster size saves time and prevents expensive reprints from miscommunication.

We run campaigns across US cities and coordinate with international vendors on cross-market projects. Measurement conversion comes up constantly. This guide covers every major poster size in centimeters, including both US standard sizes converted from inches and the ISO sizes that use metric measurements natively.

The Conversion Basics

The conversion from inches to centimeters is straightforward. One inch equals 2.54 centimeters exactly. So multiply any inch measurement by 2.54 to get centimeters. Divide centimeters by 2.54 to get inches.

For quick field math: 10 inches is approximately 25.4 cm. 20 inches is approximately 50.8 cm. 36 inches is approximately 91.4 cm. Once you know those anchor points, you can estimate any conversion quickly without a calculator.

US Standard Poster Sizes in Centimeters

Here are the most commonly used US poster sizes with their centimeter equivalents, calculated to two decimal places.

ISO Poster Sizes in Centimeters

The ISO A-series is the international standard for paper and poster sizes. These measurements are defined in millimeters, so the centimeter values are exact by design (simply divide by 10). ISO sizes are used throughout Europe, Australia, Latin America, and most of Asia.

The Most Common Poster Size in Centimeters
The US 24×36 poster converts to approximately 60.96 x 91.44 cm. In practical terms, this is roughly 61 x 91 cm. The ISO A1 size (59.4 x 84.1 cm) is the nearest international equivalent, though it is not an exact match. When working with international vendors, always specify the exact centimeter dimensions rather than relying on size name equivalencies.

Working with Centimeters in Design Software

Most professional design applications, including Adobe Illustrator, InDesign, and Photoshop, allow you to set document units to centimeters. When working on posters destined for European vendors or international campaigns, setting your document in centimeters from the start prevents conversion errors downstream.

In Adobe Illustrator: Edit menu, Preferences, Units. Set General and Artboard to Centimeters.

In Adobe InDesign: Edit menu, Preferences, Units and Increments. Set Horizontal and Vertical to Centimeters.

In Canva (online): Go to Custom Size when creating a new design. Enter dimensions in centimeters by typing the unit (e.g., “60.96 cm x 91.44 cm” for a 24×36 poster).

Setting units at the document level ensures that rulers, guides, and output specs all read in centimeters throughout the workflow. Converting individual elements after the fact is error-prone and slow.

Print Resolution in Centimeters

When working in centimeters, print resolution is typically expressed in dots per centimeter (dpcm) rather than the US standard of dots per inch (dpi). The relationship is simple: 1 dpi equals approximately 0.394 dpcm. 300 dpi equals approximately 118 dpcm.

For outdoor poster printing, the standard resolution requirement is 150 dpi at final print size for wide-format inkjet, which equals approximately 59 dpcm. For posters intended to be viewed up close (within 3 feet), 300 dpi (118 dpcm) is more appropriate.

Most print vendors operating internationally will accept files specified in dpi regardless of whether the document dimensions are in centimeters. Confirm your vendor’s preferences before sending files.

Why Centimeter Accuracy Matters More Than You Think

A fraction of a centimeter difference between a poster file and the display hardware sounds trivial. In practice, it can mean your poster doesn’t fit its frame, leaves visible white margins at the edges, or gets cropped in ways that cut off your logo or headline. These aren’t hypothetical problems. They happen on real production runs when centimeter specifications aren’t checked carefully.

The most common source of error is rounding. If a vendor rounds 59.4 cm to 60 cm, and you’ve designed your bleed to 59.4 cm, your poster might print 1.2 cm wider than designed. In most contexts that’s fine: the print is trimmed to size. But if you’re ordering unframed prints that need to fit a specific display slot, that 0.6 cm on each side is the difference between a poster that slides in and one that needs to be forced.

Always provide dimensions to two decimal places when working in centimeters. Ask your vendor to confirm the final trim size before the print run starts. A one-minute verification conversation prevents expensive reprints.

Centimeter Dimensions for Common Campaign Formats

Here are the centimeter dimensions for the formats we most commonly use in outdoor street campaigns. These are practical working dimensions used by our print vendors for real campaign production.

• Small street poster: 27.94 x 43.18 cm (11×17 in). Used for volume neighborhood coverage. High quantity, low individual cost.
• Mid-format street poster: 45.72 x 60.96 cm (18×24 in). The most versatile size for urban campaigns. Works on most available wall surfaces.
• Standard large poster: 60.96 x 91.44 cm (24×36 in). Primary format for high-visibility placements. Readable from 25 feet in good conditions.
• Large format campaign poster: 101.6 x 152.4 cm (40×60 in). Used for statement placements, wall takeovers, and high-traffic locations.

Always Double-Check Conversions Before Printing
A rounding error on a centimeter-to-inch conversion can result in a poster that does not fit its intended display space. We always verify both the inch and centimeter dimensions with our print vendor before finalizing any international or cross-market print order. One phone call before printing costs nothing. A reprint costs real money.

How Centimeter Measurements Affect File Setup for Print

Setting up print files in centimeters requires attention to bleed and margin specifications. Most print vendors specify bleed in millimeters or inches. When working in a centimeter-based document, convert bleed values accordingly.

Standard bleed for poster printing is 0.125 inches, which equals approximately 0.318 cm or 3.18 mm. For practical purposes, use 3 mm bleed when working in metric units, as most European vendors specify 3 mm as their standard bleed requirement.

Safe zone for text and important design elements should be at least 6 mm (approximately 0.24 inches) inside the trim edge. This ensures that critical content is not cut during trimming, regardless of minor press sheet movement.

European and International Poster Markets: Centimeter Standards in Practice

Understanding centimeter poster sizes is most useful when your campaign runs, or might run, in markets outside the US. Here’s a practical breakdown of how centimeter-based poster standards work in the markets where they’re most common.

United Kingdom

The UK uses the ISO A-series almost universally for print advertising. A1 (59.4 x 84.1 cm) and A2 (42 x 59.4 cm) are the workhorses of UK outdoor advertising. Bus shelter panels use custom formats standardized by the out-of-home industry, but street-level campaigns rely almost entirely on A-series sizes. UK print vendors are set up to produce A-series efficiently at scale. Order quantities, pricing, and turnaround expectations differ from US vendors.

Germany and the DACH Region

Germany, Austria, and Switzerland follow ISO standards strictly. The German standardization authority (DIN) aligned with ISO 216 decades ago. German poster vendors use DIN A-series measurements as the absolute standard. Campaigns running in German-speaking markets should be designed to A-series specifications from the start, not adapted from US formats after the fact.

Australia and New Zealand

Australia and New Zealand both use the ISO A-series. Australian transit advertising uses standardized OOH formats (many based on metric dimensions), while street-level campaigns use A1 and A2 as primary formats. The Australian outdoor advertising market has strong infrastructure for metric-format campaigns in major cities including Sydney, Melbourne, Brisbane, and Perth.

Canada

Canada officially uses the metric system but its print industry uses a hybrid of metric and US imperial sizes. Many Canadian printers work in both systems and produce both ISO A-series and US format posters. For campaigns that cross between US and Canadian markets, both format sets are often needed.

Converting Between Centimeters and Pixels for Digital Design

When designing for print in a digital workflow, you may need to convert between centimeters and pixels. Here’s the formula:

Pixels = (Centimeters / 2.54) x DPI

For an A1 poster (59.4 x 84.1 cm) at 150 DPI:

• Width: (59.4 / 2.54) x 150 = 3,508 pixels
• Height: (84.1 / 2.54) x 150 = 4,967 pixels

For the same A1 at 300 DPI:

• Width: (59.4 / 2.54) x 300 = 7,016 pixels
• Height: (84.1 / 2.54) x 300 = 9,933 pixels

These are large files. At 300 DPI, an A1 design in Photoshop will generate a file in the 200 to 400 MB range for raster designs. Work in TIFF or PSD while designing, then export to PDF for final print delivery. Never work at 72 DPI and plan to upscale for print. Upscaling a low-resolution file produces pixelated, unprintable results.

When to Specify Centimeters vs. Inches to Your Print Vendor

The practical rule: specify dimensions in the unit system your vendor uses natively. If you’re ordering from a US vendor, specify in inches. If you’re ordering from a European vendor, specify in centimeters or millimeters. If you’re unsure which system they prefer, ask before sending files. Most vendors can work in either system, but specifying in their native system reduces the risk of conversion errors.

Always include both the dimensions and the format name when communicating with vendors. Saying “I need an A1 poster at 59.4 x 84.1 cm” is clearer than just saying “I need a 59.4 x 84.1 cm poster,” because the format name gives the vendor a double-check reference. If the dimensions don’t match A1, they’ll flag it before printing.

For campaigns that run at the same time in the US and internationally, we create two separate print-ready files: one in US dimensions, one in ISO metric dimensions. The design adapts to the small size differences between formats. This approach prevents the cropping and white-border issues that arise from forcing one file to fit two incompatible size standards.

Frequently Asked Questions