โ๏ธ C4 Envelope
| Millimeters | 229 ร 324 mm |
| Centimeters | 22.9 ร 32.4 cm |
| Inches | 9.02 ร 12.76 in |
| Points | 649 ร 918 pt |
| Picas | 54.1 ร 76.5 pc |
| Pixels (300dpi) | 2705 ร 3827 px |
| Pixels (72ppi) | 649 ร 918 px |
โ๏ธ DL Envelope
| Millimeters | 110 ร 220 mm |
| Centimeters | 11.0 ร 22.0 cm |
| Inches | 4.33 ร 8.66 in |
| Points | 312 ร 624 pt |
| Picas | 26.0 ร 52.0 pc |
| Pixels (300dpi) | 1299 ร 2598 px |
| Pixels (72ppi) | 312 ร 624 px |
Area: 1 C4 = 2 ร DL (DL is half the area). Scaling factor: 1/โ2 โ 0.7071 per side.
DL is the standard business envelope size worldwide โ this tool helps you scale down from C4 for professional correspondence and invoicing.
DL = C4 ร 2 ยท Scale factor = 1/โ2 โ 0.7071 per side1 C4 envelope splits into exactly 2 DL envelopes (or 1 DL = 0.5 C4).
๐ What is C4 Envelope Size?
C4 is a medium envelope size in the ISO 216 C-series. Its dimensions are 229 ร 324 mm (9.0 ร 12.8 inches), with an area of 0.074 mยฒ. C4 is designed to hold A4 paper without folding (A4 is 210 ร 297 mm). It's the standard envelope size for professional correspondence, business mail, and official documents. C4 is exactly double the area of DL, making it the most common professional envelope size worldwide.
๐ What is DL Envelope Size?
DL (Dimension Lengthwise) is a popular envelope size defined in ISO 269. Its dimensions are 110 ร 220 mm (4.3 ร 8.7 inches), with an area of 0.024 mยฒ. DL is designed to hold A4 paper folded into thirds (or A5 folded in half). It's the standard business envelope size for invoices, statements, and everyday correspondence. DL is exactly half the area of C4, making it the most common envelope size for business mail.
๐งฎ The Math: How C4 Becomes DL
The ISO 216 C-series is based on the geometric mean of the A and B-series. The DL size is defined separately but follows the same proportional logic. Each step down (C4 โ DL) approximately halves the area. The side lengths decrease by a factor of 1/โ2 โ 0.7071.
- Width: 229 mm ร (1/โ2) โ 162 mm (but DL is 110 mm)
- Height: 324 mm ร (1/โ2) โ 229 mm (but DL is 220 mm)
- Area: 0.074 mยฒ รท 2 = 0.037 mยฒ (DL is 0.024 mยฒ)
Formula: 1 C4 โ 2 ร DL (in area). So, if you have 1 C4 envelope, you can create approximately 2 DL envelopes from it (or 1 DL โ 0.5 C4).
๐ Quick Conversion Table: C4 to DL
| C4 Envelopes | DL Equivalent | Scale factor (side) | Realโworld use |
|---|---|---|---|
| 0.5 C4 | 1 DL | 100% | Single business envelope |
| 1 C4 | 2 DL | 70.7% (reduce) | Two business envelopes |
| 2 C4 | 4 DL | 50% (half width/height) | Four business envelopes |
| 5 C4 | 10 DL | 31.6% | Bulk mailing |
| 10 C4 | 20 DL | 22.4% | Large mailing campaign |
| 25 C4 | 50 DL | 14.1% | Marketing mailer |
| 50 C4 | 100 DL | 10% | Large-scale mail |
| 100 C4 | 200 DL | 7.1% | Massive mailing |
โ๏ธ RealโWorld Examples: C4 to DL in Action
- ๐ฌ Business Mail: C4 is used for official documents and professional correspondence. When you need to produce standard DL business envelopes for invoices and statements, this converter tells you exactly how many DL envelopes you can create from each C4 envelope.
- ๐ Invoices & Statements: DL is the most common envelope for invoices, statements, and everyday business mail. C4 is used for larger documents. Understanding the scaling helps with consistent branding.
- ๐ฆ Marketing Materials: C4 mailers can be designed, and then the same artwork can be scaled to DL for smaller-format mailers or handouts.
- ๐ข Office Correspondence: C4 is used for official documents and large mail. DL is used for standard business letters and invoices. Convert between them for consistent document management.
- ๐จ๏ธ Printing & Production: Understanding C4 to DL conversion is essential for print production, especially when printing multiple envelope sizes from the same sheet.
๐ก Professional Tips for C4 to DL Scaling
๐ฏ Resolution & Quality
When scaling from C4 to DL, if your original is 300 DPI, the resulting DL will be ~424 DPI โ actually higher quality! This is because you're concentrating the same pixels into a smaller area. For best results, design at 300 DPI at C4 for sharp DL prints.
๐ CโSeries vs. DL
C4 is designed to hold A4 paper without folding. DL is designed to hold A4 paper folded into thirds. This makes DL the most common business envelope size for letters and invoices.
๐ฐ Printing & Mailing Efficiency
Printing 2 DL envelopes from 1 C4 sheet can save paper and costs. Many professional printers support C-series and DL sizes โ check your printer settings.
๐ Professional Correspondence
DL is the standard for business mail, invoices, and professional correspondence. Use this converter to plan your envelope sizes for professional communications.
โ Frequently Asked Questions (C4 to DL)
Q: How many DL envelopes equal 1 C4?
A: Approximately 2 DL envelopes make 1 C4 in terms of area. You can fit two DL envelopes on one C4 sheet.
Q: What is the scaling factor from C4 to DL?
A: Each side is scaled by approximately 1/โ2 โ 0.7071, meaning you reduce the width and height by 29.3%.
Q: Can I fit a C4 document into a DL envelope?
A: Yes, by scaling it down to approximately 70.7% on each dimension. The document will fit, but text and details will be smaller.
Q: What is the difference in area between C4 and DL?
A: C4 has approximately double the area of DL (0.074 mยฒ vs. 0.024 mยฒ).
Q: Is C4 bigger than DL?
A: Yes, C4 is larger. C4 is the next size up from DL. 1 C4 โ 2 ร DL.
Q: What is C4 used for?
A: C4 is used for official documents, professional correspondence, and A4-size mail.
Q: What is DL used for?
A: DL is used for business mail, invoices, statements, and everyday correspondence.
Q: Can I print C4 on DL?
A: Yes, by scaling down to approximately 70.7%. Most printers support this scaling. This tool helps you understand the exact ratio.
Q: What does DL stand for?
A: DL stands for "Dimension Lengthwise" and is defined in ISO 269 for envelopes.
๐ Why Accurate C4โtoโDL Conversion Matters
Accurate scaling between C4 and DL is essential for professional mail, envelope production, and document management. Whether you're preparing an invoice, designing a business letter, or planning a mailing campaign, this tool ensures your envelopes fit perfectly every time. Inaccurate scaling can lead to wasted paper, misaligned designs, and costly reprints.
๐ Global Standards & Professional Usage
The Cโseries (ISO 216) and DL (ISO 269) are used worldwide for professional mail and correspondence. C4 is the standard for official documents, while DL is the most common business envelope size globally. This tool supports professional envelope size conversions for users worldwide.
๐ The Full CโSeries & DL Hierarchy
- DL = 110 ร 220 mm โ standard business envelopes, invoices, statements
- C6 = 114 ร 162 mm โ invitations, greeting cards
- C5 = 162 ร 229 mm โ flyers, medium mail
- C4 = 229 ร 324 mm โ standard mail, A4 documents, business envelopes
- C3 = 324 ร 458 mm โ large mail, catalogs, A3 documents
- C2 = 458 ร 648 mm โ oversized mail, A2 documents
- C1 = 648 ร 917 mm โ very large mail, posters
- C0 = 917 ร 1297 mm โ extremely large mail, display
Each step up approximately doubles the area, making the system intuitive and easy to scale.
๐ Explore More Envelope & Mail Tools
Check out our other converters: DL to C4, C6 to C5, C5 to C4, C4 to C3, C3 to C2, and C2 to C3. All designed to make your print and mail workflows smoother.