August 11, 2026
The average poster board is 22×28 inches. But that’s just the beginning. Here’s everything you need to know about poster board sizes, what they’re used for, and how to pick the right one.
People ask us about poster board sizes constantly. Some are science fair students. Some are craft supply shoppers. A lot are first-time clients who have never ordered a print campaign before and want to understand what they’re working with before they commit to anything.
The honest answer is this: the “average” poster board in the United States is 22×28 inches. That’s the size you’ll find at most office supply stores, craft stores, and big-box retailers. It’s what most people picture when they hear “poster board.” But that’s only one size in a range that spans from small hobby boards to very large display formats.
Understanding poster board sizes means understanding what each size is designed to do and which applications each one actually suits. This guide covers all of that.
Before we get into sizes, it’s worth being precise about what “poster board” actually means, because the term gets used in a few different ways.
In everyday use, a poster board is a thick, rigid piece of paper-based material used for making signs, displays, and projects. Craft stores sell it in sheets. The material is stiffer than regular paper but lighter and less expensive than foam board or mounted panels. It bends rather than snapping. It takes markers, paint, and glue well.
In the print and advertising industry, “poster board” sometimes refers to the backing material used to mount printed posters. This is typically a heavier stock, sometimes foam-core or corrugated plastic. The dimensions are different and the materials are more durable.
This guide covers both contexts, starting with the common craft/school/display use, then touching on print industry applications.
Here are the standard poster board sizes you’ll find at retail outlets and print shops:
| Poster Board Size | Dimensions (inches) | Area (sq. in.) | Common Use |
|---|---|---|---|
| Small | 14 x 22 in | 308 sq. in. | Small projects, signs, notices |
| Standard / Average | 22 x 28 in | 616 sq. in. | School projects, displays, events |
| Large | 24 x 36 in | 864 sq. in. | Advertising, large event displays |
| Tri-fold | 36 x 48 in (folded: 16 x 36) | 1,728 sq. in. | Science fairs, presentations |
| Extra Large | 36 x 48 in | 1,728 sq. in. | Trade show, large format display |
The 22×28 is by far the most widely stocked size. Walk into any Staples, Target, Walmart, or Michael’s and you’ll find 22×28 poster boards in multi-packs. They’re cheap, easy to find, and the right size for most school and hobby projects.
The 24×36 is the standard size for advertising poster boards. That’s where the line between “school supply” and “print campaign material” begins to blur. Print shops stock 24×36 because it’s the most common single-sheet poster size for commercial use.
The 22×28 poster board became the standard because it’s a practical size for display work that doesn’t require a large-format printer. It’s big enough to see from across a room. It’s small enough to carry under your arm. It fits in most shopping bags.
The 22×28 corresponds to what’s sometimes called a “half-size” in print contexts. A standard tabloid sheet is 11×17. Double that in each dimension and you get 22×34, close to but not exactly 22×28. The 22×28 evolved as a practical retail standard more than a mathematical derivation.
For school science fairs, the 22×28 is a common single-panel board. Two of them side by side give you 44×28. Three together make 66×28, which is often used as a backdrop for display projects. When you see students working on trifold boards, the panels on either side are usually 22×28 or close to it.
Quick reference: The most common poster board sizes in the US are 14×22, 22×28, and 24×36. The 22×28 is the “standard” at retail. The 24×36 is the standard for print advertising. Most people asking about “average” are thinking of the 22×28.
People often want to know how the standard 22×28 poster board compares to what commercial printers produce. Here’s the relationship:
If you’re planning to print something commercially and mount it on a poster board, match the print size to the board size, or buy a board slightly larger than your print to leave a border.
The tri-fold poster board deserves its own section because it’s one of the most searched formats. These boards fold into three panels, with the center panel usually being the widest. When unfolded, a typical tri-fold is 36 inches wide by 48 inches tall.
The folded dimensions vary by brand. Most common tri-folds fold down to about 16 inches wide by 36 inches tall. This makes them easy to transport and store. The two side panels fold in front of the center panel.
Tri-fold boards are the dominant format for school science fairs, academic conferences, and trade show table displays. They stand on their own. They don’t require any external support. For quick, portable displays, they’re hard to beat.
The material is usually the same as standard poster board. Some versions have a corrugated inner layer for extra stiffness. Others are made from foam core rather than standard board material, which is heavier but even more rigid.
In advertising and marketing, “poster board” often means something different from what craft stores sell. Print shops and sign companies use the term to describe a mounted or backed print product.
A mounted print poster board consists of a commercially printed image, a backing material (usually foam core, PVC foam, or aluminum composite), and sometimes a laminated front surface. The dimensions match standard advertising poster sizes: 18×24, 24×36, 36×48, and so on.
These mounted poster boards are significantly more durable than the foam-core or paper variety from craft stores. They stand up to handling and environmental exposure. They look more professional in retail and event contexts. They cost considerably more to produce.
If you’re planning a commercial display or promotional campaign, you’re probably looking at mounted poster boards from a print shop rather than craft-store poster board. The two products serve different needs.
For advertising campaigns: The standard mounted poster board for street and retail use is typically 24×36 or 18×24. These are commercially printed, often on heavy stock paper or vinyl, and may be backed or laminated. They’re not what you buy at the craft store.
Here’s a practical guide to picking the right size:
The 22×28 is your default. It’s universally available, inexpensive, and the right size for most classroom and science fair requirements. If the project requires a self-standing display, go with a tri-fold at 36×48.
The 24×36 gives you a professional-looking display that’s visible from across a room. Most local print shops can print to this size at reasonable cost. Pair a professionally printed 24×36 with a foam-core backing for a clean, sturdy display sign.
The 24×36 is the starting point. High-traffic locations, venues on busy blocks, and street-level placements all benefit from the 24×36 or larger. Our crews place thousands of these per month across New York, Chicago, LA, and other major cities.
The 36×48 tri-fold or a printed 36×48 banner is typical for trade show work. For table-top displays, the tri-fold at 36×48 is the industry standard. For booth backdrops, you’ll need larger format work, typically 8 feet wide and up.
For more on how we approach poster campaigns for advertising and brand promotion, see our poster advertising services page.
If you’re working with international suppliers or referencing European print specs, you’ll need the metric equivalents. Here’s how the common US poster board sizes convert:
None of these correspond exactly to ISO A-series sizes. The A1 size (594 x 841 mm, or about 23.4 x 33.1 inches) is the closest European equivalent to the US 22×28, but it’s not the same. If you’re ordering from a European supplier and need a US-standard size, specify the exact inch measurements. Don’t assume A1 and 22×28 are interchangeable.
US retailers and print shops work in inches. When you see poster board listings online, dimensions listed in centimeters typically indicate the product ships from overseas. Verify measurements before purchasing for any project where exact size matters.
Size isn’t just a logistical decision. It directly affects how much information you can put on the board and how far away people can read it. This matters a lot in advertising.
A general rule: the minimum readable type size at a given distance is roughly 1 inch of letter height per 10 feet of viewing distance. On a 22×28 board, you have maybe 10 inches of usable width for headline text. That’s readable from about 8 to 10 feet. On a 24×36, you gain an extra 2 inches of width, which lets you run slightly larger type and maintain readability from 12 to 15 feet.
In street advertising, viewing distance matters. People walk past, they’re not standing still and reading carefully. You need big type, a clear hierarchy, and very little copy. Most effective street-level poster boards have:
The 24×36 format gives you the most usable space to execute that kind of design. The 22×28 is workable, but tight. The 18×24 is small enough that you have to sacrifice either size of type or amount of content.
In our experience running campaigns across New York, Chicago, and Los Angeles, the 24×36 poster board hits the sweet spot between visibility and cost per placement. It’s big enough to see from the street. It’s small enough to fit on crowded walls and in windows without looking awkward.
The 24×36 is the workhorse of street-level advertising. You see it in specific places. Here’s where these boards typically live:
For brand campaigns, we rarely rely on a single placement location. A effective poster board campaign spreads across dozens or hundreds of locations in a target neighborhood. The repetition is part of what makes it work. People see it at the coffee shop, then at the bar, then on the corner. That repetition builds awareness faster than a single premium placement.
The poster board itself is only part of the equation. How you display it matters too.
The simplest option. Tape, staples, or adhesive strips. This is how most promotional poster boards go up in bars, shops, and on outdoor surfaces. Quick to install, quick to take down. Not appropriate for premium contexts where you need a finished look.
A printed sheet mounted onto foam core board creates a rigid, professional-looking panel. These stand on their own with an easel or hang flat on a wall. Good for trade show displays, retail environments, and any context where you want the board to look finished rather than stuck up with tape.
A-frame sidewalk signs typically accept boards up to 22×28 or 24×36. The frame provides stability outdoors and in high-traffic areas. Easels are better suited for indoor environments: galleries, lobbies, event entrances. If you need a board to stand without wall support, plan your size around the frames available to you.
For retail and corporate environments, poster boards sit inside thin metal or acrylic snap frames. These come in standard sizes: 18×24, 22×28, 24×36. If you’re designing for these frames, you need to leave a small border around your design, about a quarter inch minimum, to account for the frame edge covering part of the board.
Laminating a poster board adds significant durability and a finished appearance. Gloss lamination makes colors pop. Matte lamination reduces glare and gives a more premium look. Laminated boards hold up better outdoors and can be wiped clean. The cost per board goes up, but for any display that needs to last more than a few days or survive weather exposure, lamination is worth it.
The average poster board in the US is 22×28 inches. This is the most widely stocked size at retail stores including Walmart, Target, Staples, and craft supply chains. For advertising purposes, the average size shifts to 24×36 inches.
The most common poster board size at Walmart and Target is 22×28 inches. Some stores also stock 14×22 and occasionally 28×40. The 22×28 size is sold in white, black, and assorted color packs.
No. A 22×28 has 616 square inches of area. A 24×36 has 864 square inches. The 24×36 is about 40% larger in area. They’re different products for different uses. The 22×28 is a retail/craft standard. The 24×36 is a print advertising standard.
Most tri-fold poster boards open to 36×48 inches and fold down to approximately 16×48 inches. The center panel is typically wider than the two side panels. Dimensions vary slightly by brand.
Standard poster board from retail stores typically weighs between 100 and 160 grams per square meter, or roughly 60 to 90 lb in US paper weight terms. It’s stiffer than standard writing paper but not as rigid as foam core or mounted board.
Most science fair requirements specify a tri-fold board or a flat board of a certain maximum size. The tri-fold at 36×48 opened is the most common science fair standard. Check your specific event guidelines, as requirements vary by school and grade level.
You can run standard poster board through some large-format printers, but most inkjet and laser office printers won’t accept the material. For best results, print on paper or vinyl at a print shop and then mount the print to the board. Or order a print directly on poster board stock from a commercial printer.
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American Guerrilla Marketing — Los Angeles
Street-level campaigns in Los Angeles and nationwide. Wheatpasting, LED trucks, street teams, and more.
(646) 776-2770
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