Ever wondered why some notebooks feel just right in your hands? That’s the B-series paper size working its magic. While most Americans know A4 paper, the B-series remains a mystery—yet it’s everywhere in our books, planners, and posters.

This guide breaks down B paper sizes from the massive B0 to the tiny B13, plus oversized formats and specialty variants. You’ll discover which size fits your project and why the ISO B-series bridges gaps the A-series can’t fill.

Also we’ve included comprehensive measurements in millimeters (mm), centimeters (cm), meters (m), inches (in), points (pt), picas (pc), and pixels (px) at 300 PPI to serve designers, printers, and digital creators alike.

What Are B-Series Paper Sizes?

The B-series paper size is an international standard defined by ISO 216. It sits perfectly between consecutive A-series sizes, offering dimensions that A-sizes simply can’t provide.

B-series paper originated in Germany in the 1920s and became a global standard after World War II. Each B-size is approximately 50% larger in area than its corresponding A-size. For example, B5 paper fills the gap between A5 and A4.

The magic lies in the √2 ratio. When you cut a B-size sheet in half, you get the next smaller size. This geometric progression means B1 is half of B0, B2 is half of B1, and so on.

Complete B-Series Paper Sizes Chart

Our comprehensive B-series paper size chart covers every format from the massive B0 down to the tiny B13, plus oversized variants and specialty formats.

Standard ISO B-Series Chart

The Standard ISO B-Series chart presents all 14 officially recognized B paper sizes in one comprehensive reference table.

Oversized B-Series Formats

Oversized B-Series formats extend beyond standard ISO specifications to accommodate professional printing requirements.

These larger variants—B0+, B1+, B1 XL, and B2+—add extra margins around standard B-sizes specifically for bleed allowances, trim marks, and color registration bars that commercial printers need.

Specialty Formats: RB & SRB Paper Sizes

RB (Raw B) sizes are the uncut sheets commercial printers receive. They’re slightly larger than standard B-series dimensions, typically adding 30-50mm to each edge. This extra space accommodates crop marks, color bars, and registration marks.

SRB (Supplementary Raw B) formats extend even further. Pre-press operations use SRB when multiple pages print on one large sheet.

Common Uses and Applications of Every B Paper Size

Large Format B-Sizes

B0 paper is the grandfather of all B-sizes at 1000 × 1414 mm (39.4 × 55.7 inches). It’s massive—perfect for billboard posters and large-scale architectural plans. You won’t find this in regular stores.

B1 dimensions measure 707 × 1000 mm (27.8 × 39.4 inches). Print shops use B1 for professional posters, trade show graphics, and wall calendars. It’s half the size of B0, following that perfect √2 ratio.

B2 paper size comes in at 500 × 707 mm (19.7 × 27.8 inches). Restaurants love B2 for menu boards. It’s also popular for medium-sized posters and flip charts in conference rooms.

Mid-Range B-Sizes

B3 format measures 353 × 500 mm (13.9 × 19.7 inches). Regional newspapers often print on B3. It’s also a favorite for small posters and tabloid-style publications.

B4 paper at 250 × 353 mm (9.8 × 13.9 inches) is common in academic settings. Students use it for art pads and project folders. It’s slightly larger than US Legal size.

B5 is the rockstar of B-series at 176 × 250 mm (6.9 × 9.8 inches). Walk into any bookstore in Europe or Japan, and you’ll see B5 notebooks everywhere.

It’s the standard size for composition books, planners, and trade paperbacks.

Small Format B-Sizes

B6 paper size measures 125 × 176 mm (4.9 × 6.9 inches). It’s perfect for postcards, greeting cards, and pocket-sized books. Many manga volumes use B6 format.

B7 dimensions are 88 × 125 mm (3.5 × 4.9 inches). Passport photos in some countries follow B7 specifications. Small notepads and memo pads often use this size.

B8 format at 62 × 88 mm (2.4 × 3.5 inches) is roughly playing card size. Some business cards and ticket stubs use B8 dimensions, though it’s less common than standard business card sizes.

Micro B-Sizes

B9 through B10 enter micro-territory. B9 measures 44 × 62 mm (1.7 × 2.4 inches), while B10 is 31 × 44 mm (1.2 × 1.7 inches). These sizes work for labels, stamps, and specialty printing applications.

B11, B12, and B13 are incredibly small. B11 is 22 × 31 mm, B12 measures 15 × 22 mm, and B13 comes in at 11 × 15 mm. Industrial labeling and micro-photography are their primary domains. Most people never encounter these sizes.

Oversized Formats

B0+ paper measures 1118 × 1580 mm (44 × 62.2 inches). Professional printers use this for jobs requiring bleed margins. The extra space ensures no white edges after trimming.

B1+ dimensions are 720 × 1020 mm (28.3 × 40.2 inches). High-end poster production relies on B1+ format for gallery-quality prints with perfect edges.

B1+ (B1XL) specifically measures 750 × 1050 mm (29.5 × 41.3 inches). This variant gives maximum flexibility for large format printing with generous bleed allowances. Commercial printers stock B1 XL for premium poster jobs.

B2+ paper at 520 × 720 mm (20.5 × 28.3 inches) serves mid-sized professional printing. It’s the sweet spot for art reproductions and marketing materials that need perfect finishing.

B-Series vs A-Series Paper

B-series paper is always larger than the corresponding A-series size. Specifically, each B-size is approximately 1.5 times the area of its A-series counterpart. For example, B5 paper (176 × 250 mm) is noticeably bigger than A5 (148 × 210 mm).

The relationship follows precise mathematics. B4 dimensions (250 × 353 mm) sit geometrically between A4 (210 × 297 mm) and A3 (297 × 420 mm). This positioning makes B-sizes perfect when A-sizes feel slightly wrong for your project.

Price differences matter in the US market. A-series paper costs less domestically because it’s more common. A ream of A4 paper might cost $5-8, while B5 paper could run $12-15 for the same quantity. Bulk ordering from international suppliers helps reduce this gap.

Availability challenges frustrate American designers. Office supply chains like Staples and Office Depot rarely stock B-series paper. You’ll need specialty stationery stores or online retailers.

Printer compatibility presents another hurdle. Most consumer printers in the US handle Letter (8.5 × 11″) and Legal (8.5 × 14″) sizes perfectly. B5 paper fits most printers’ maximum paper width, but you’ll need to configure custom paper settings.

FAQ’s (B-Series Paper Sizes)

Which is bigger, A3 or B3?

B3 paper is bigger than A3. B3 dimensions measure 353 × 500 mm (13.9 × 19.7 inches), while A3 measures 297 × 420 mm (11.7 × 16.5 inches). B3 offers about 50% more surface area than A3—that’s a significant difference for design and layout work.

Is B5 or B6 bigger?

B5 is bigger than B6. The B-series follows a simple rule: lower numbers mean larger sizes. B5 paper measures 176 × 250 mm, while B6 measures only 125 × 176 mm.

Which is bigger, B5 or B4?

B4 paper is bigger than B5. B4 dimensions are 250 × 353 mm (9.8 × 13.9 inches) compared to B5’s 176 × 250 mm (6.9 × 9.8 inches). B4 contains exactly twice the surface area of B5—cut a B4 sheet in half and you get two B5 sheets.

Is B1 or B2 bigger?

B1 is bigger than B2. B1 paper measures 707 × 1000 mm (27.8 × 39.4 inches), while B2 is 500 × 707 mm (19.7 × 27.8 inches). Remember: in both A-series and B-series paper sizes, smaller numbers indicate larger sheets.

Which is bigger, A5 or B5 or A4?

A4 is the biggest, followed by B5, then A5. A4 dimensions are 210 × 297 mm (8.3 × 11.7 inches), B5 measures 176 × 250 mm (6.9 × 9.8 inches), and A5 is 148 × 210 mm (5.8 × 8.3 inches). B5 perfectly bridges the gap between A5 and A4.

Is B2 the same as A2 paper?

No, B2 and A2 are different sizes. B2 paper measures 500 × 707 mm (19.7 × 27.8 inches), while A2 is 420 × 594 mm (16.5 × 23.4 inches). B2 is significantly larger—about 41% more surface area than A2. They’re designed for different purposes within the ISO paper size system.

What is B5 paper commonly used for?

B5 paper dominates the notebook and journal market outside North America. Students worldwide use B5 composition books for note-taking. Publishers choose the B5 format for textbooks, especially in Japan and Europe. Planners, bullet journals, and business notebooks overwhelmingly favor B5 dimensions (176 × 250 mm).

What are B0+ and B1+ sizes used for?

B0+ and B1+ formats serve professional printing with bleed margins. B0+ measures 1118 × 1580 mm, adding extra space around standard B0. B1+ at 720 × 1020 mm (and B1 XL at 750 × 1050 mm) accommodates crop marks and bleed allowances.

When should I use RB or SRB paper sizes?

Use RB (Raw B) and SRB (Supplementary Raw B) sizes for commercial printing projects. If you’re running a print shop or preparing files for professional offset printing, these formats accommodate registration marks and color bars.

RB paper sizes are essential for jobs requiring precise color matching and alignment. Home and small office users stick with standard B-series dimensions.

Are B-series sizes available in US stores?

B-series paper is rare in American retail stores. Major chains like Staples, Office Depot, and Walmart don’t regularly stock B5 paper or other B-formats.

Can I print B5 on a standard US printer?

Yes, most US printers handle B5 paper. B5 dimensions (176 × 250 mm or 6.9 × 9.8 inches) fit within standard printer maximum widths.

Conclusion

B-series paper sizes offer precision where A-series falls short. From massive B0 posters to tiny B13 labels, this system covers every printing need with mathematical elegance.

B5 notebooks and B4 folders dominate international markets for good reason—they’re sized just right. While US availability remains limited, understanding B-series dimensions opens global design possibilities. Whether you’re creating textbooks, posters, or professional graphics, the B-series delivers the perfect fit.