Area: 1 B3 = 2 × B4 (B3 is double the area). Scaling factor: √2 ≈ 1.4142 per side.
B4 is the standard for magazines and larger notebooks — this tool helps you scale up to B3 for posters and book covers.
B3 = B4 × 0.5 · Scale factor = √2 ≈ 1.4142 per side2 B4 sheets combine to make 1 B3 sheet (or 1 B3 = 2 B4).
📏 What is B4 Paper Size?
B4 is a medium-large paper size in the ISO 216 B-series. Its dimensions are 250 × 353 mm (9.8 × 13.9 inches), with an area of 0.08825 m². B4 is widely used for magazines, larger notebooks, and professional printing. It sits between A4 (210 × 297 mm) and A3 (297 × 420 mm) in size, offering a versatile format for publishing and design. B4 is exactly half the area of B3, making it a common choice for magazine pages and notebook signatures.
📄 What is B3 Paper Size?
B3 is a large paper size in the ISO 216 B-series. Its dimensions are 353 × 500 mm (13.9 × 19.7 inches), with an area of 0.1765 m². B3 is the go-to size for posters, book covers, and professional printing projects. It's also popular for architectural presentations and large-format marketing materials. B3 is exactly double the area of B4, making it a natural step up for more impactful designs and publications.
🧮 The Math: How B4 Becomes B3
The ISO 216 B-series is based on the geometric mean between A-series sizes. Each step up (B4 → B3) doubles the area. The side lengths increase by a factor of √2 ≈ 1.4142.
- Width: 250 mm × √2 ≈ 353 mm
- Height: 353 mm × √2 ≈ 500 mm
- Area: 0.08825 m² × 2 = 0.1765 m²
Formula: 1 B3 = 2 × B4 (in area). So, if you have 2 B4 sheets, they can be combined to form 1 B3 sheet (or 1 B4 = 0.5 B3).
📊 Quick Conversion Table: B4 to B3
| B4 Sheets | B3 Equivalent | Scale factor (side) | Real‑world use |
|---|---|---|---|
| 0.5 B4 | 0.25 B3 | 100% | Small magazine page |
| 1 B4 | 0.5 B3 | 141.4% (enlarge) | Single magazine spread |
| 2 B4 | 1 B3 | 200% (double width/height) | Full poster page |
| 4 B4 | 2 B3 | 282.8% | Book cover spread |
| 5 B4 | 2.5 B3 | 316.2% | Large publication |
| 10 B4 | 5 B3 | 447.2% | Book chapter |
| 25 B4 | 12.5 B3 | 707.1% | Book volume |
| 50 B4 | 25 B3 | 1000% | Large-format catalog |
🖨️ Real‑World Examples: B4 to B3 in Action
- 📖 Magazine Publishing: B4 is a common size for magazine pages. When you need to scale up to B3 for larger formats or promotional materials, this converter tells you exactly how many B4 designs fit into a B3 layout.
- 🖼️ Poster Printing: B4 is used for medium-sized posters and book covers. B3 offers a larger format for more impactful displays.
- 📚 Book Publishing: B4 is used for book signatures and interior pages. B3 is used for book covers and dust jackets. Understanding the scaling helps with production planning.
- 🏛️ Architectural Presentations: B4 is used for detailed floor plans and sections. B3 is used for overall building layouts and presentation boards.
- 📬 Marketing Materials: B4 flyers are common for professional handouts. B3 offers more space for detailed marketing content.
💡 Professional Tips for B4 to B3 Scaling
🎯 Resolution & Quality
When scaling from B4 to B3, if your original is 300 DPI, the resulting B3 will be ~212 DPI — still acceptable for most printing. For high-quality prints, design at 600 DPI at B4 to get ~424 DPI at B3.
📐 B‑Series vs. A‑Series
B-series sizes are larger than A-series sizes at the same number. For example, B4 (250 × 353 mm) is larger than A4 (210 × 297 mm). Use B-series when you need more space than A-series offers.
💰 Printing Efficiency
Printing 2 B4 pages from 1 B3 sheet can save paper and costs. Many professional printers support B-series paper sizes — check your printer settings.
📂 Magazine Production
B4 is a common size for magazine pages. When planning a magazine, understanding how B4 converts to B3 helps with cover design and production planning.
❓ Frequently Asked Questions (B4 to B3)
Q: How many B4 sheets equal 1 B3?
A: Exactly 2 B4 sheets make 1 B3 in terms of area. You can fit two B4 pages on one B3 sheet.
Q: What is the scaling factor from B4 to B3?
A: Each side is scaled by √2 ≈ 1.4142, meaning you enlarge the width and height by 41.4%.
Q: Can I fit a B4 document onto a B3 sheet?
A: Yes, by scaling it up to 141.4% on each dimension. The document will fit, with more white space around it.
Q: What is the difference in area between B4 and B3?
A: B3 has exactly double the area of B4 (0.1765 m² vs. 0.08825 m²).
Q: Is B4 bigger than B3?
A: No, B3 is larger. B3 is the next size up from B4. 1 B3 = 2 × B4.
Q: What is B4 used for?
A: B4 is used for magazines, larger notebooks, and professional printing.
Q: What is B3 used for?
A: B3 is used for posters, book covers, and large-format publications.
Q: How does B‑series compare to A‑series?
A: B-series sizes are about 1.2× larger than A-series at the same number. For example, B4 is between A4 and A3 in size.
📈 Why Accurate B4‑to‑B3 Conversion Matters
Accurate scaling between B4 and B3 is essential for professional printing, magazine production, and document management. Whether you're preparing a magazine, designing a book cover, or planning a marketing campaign, this tool ensures your documents fit perfectly every time. Inaccurate scaling can lead to wasted paper, misaligned designs, and costly reprints.
🌐 Global Standards & Professional Usage
The B‑series (ISO 216) is used alongside the A‑series in many countries. B-series sizes are particularly popular in magazine publishing, book production, and professional design. This tool supports professional paper size conversions for users worldwide.
📐 The Full B‑Series Hierarchy
- B10 = 31 × 44 mm – very small tags
- B9 = 44 × 62 mm – small tickets
- B8 = 62 × 88 mm – small notepads, tags
- B7 = 88 × 125 mm – pocket notebooks, passports
- B6 = 125 × 176 mm – small books, notepads
- B5 = 176 × 250 mm – medium books, notebooks
- B4 = 250 × 353 mm – magazines, large books
- B3 = 353 × 500 mm – posters, book signatures
- B2 = 500 × 707 mm – large posters, book covers
- B1 = 707 × 1000 mm – large posters, banners
- B0 = 1000 × 1414 mm – display boards, billboards
Each step up doubles the area, making the system intuitive and easy to scale.
🔗 Explore More Paper & Print Tools
Check out our other converters: B3 to B2, B2 to B1, B1 to B0, A4 to A3, A3 to A4, Letter to A4, PX to MM, and DPI Calculator. All designed to make your print and design workflows smoother.