Calculate exact image dimensions when converting PDF to JPG/PNG
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Convert PDF to JPG →When converting PDFs to images, resolution (measured in DPI - dots per inch) directly determines output image dimensions, quality, and file size. Our calculator helps you predict exact pixel dimensions and file sizes before conversion, ensuring optimal results for your specific needs—whether web display, professional printing, or long-term archival.
| DPI | Letter Size (pixels) | Megapixels | JPG Size | Best For |
|---|---|---|---|---|
| 72 DPI | 612 × 792 | 0.5 MP | 50-100 KB | Web display, email, screen viewing only |
| 150 DPI | 1,275 × 1,650 | 2.1 MP | 200-400 KB | General purpose, presentations, documentation |
| 300 DPI | 2,550 × 3,300 | 8.4 MP | 800 KB-1.5 MB | Professional printing, high-quality documents |
| 600 DPI | 5,100 × 6,600 | 33.7 MP | 3-5 MB | Archival, legal docs, OCR, fine detail preservation |
| 1200 DPI | 10,200 × 13,200 | 134.6 MP | 12-20 MB | Professional archival, extreme detail requirements |
72 DPI (Web/Screen): Designed specifically for digital display, 72 DPI produces compact files perfect for websites, emails, and screen presentations. A standard letter-size page becomes 612×792 pixels—ideal for web use but insufficient for printing. Choose this when files will only be viewed on screens and file size is critical. Images appear sharp on monitors but pixelated when printed.
150 DPI (General Purpose): The sweet spot for most users, 150 DPI creates 1,275×1,650 pixel images suitable for presentations, documentation, and casual printing. File sizes remain manageable (200-400 KB for JPG) while quality is acceptable for most business applications. This setting balances quality with practicality—good enough for 95% of use cases.
300 DPI (Print Quality): Professional printing standard recognized worldwide. 300 DPI generates 2,550×3,300 pixel images with excellent detail for high-quality prints, professional documents, publications, and marketing materials. Recommended for anything that will be professionally printed. Images look crisp at actual size and maintain quality when printed on high-quality printers.
600 DPI (Archival/OCR): Maximum quality for document preservation and optical character recognition. Creates 5,100×6,600 pixel images (33.7 megapixels) with exceptional detail. Essential for legal documents requiring every signature detail, historical preservation where originals may deteriorate, and documents requiring accurate OCR text extraction. Files are large (3-5 MB JPG, 8-15 MB PNG) but capture every nuance.
1200 DPI (Professional Archive): Extreme resolution rarely needed outside specialized applications. Creates 10,200×13,200 pixel images (134.6 megapixels). Used for fine art reproduction, detailed technical drawings, and situations where extreme magnification may be required. Files are very large (12-20 MB JPG, 30-60 MB PNG).
| Feature | JPG (JPEG) | PNG |
|---|---|---|
| Compression Type | Lossy (discards some data) | Lossless (preserves all data) |
| File Size | ~10% of uncompressed (much smaller) | ~30% of uncompressed (3x larger than JPG) |
| Quality Loss | Slight, usually imperceptible | None (pixel-perfect) |
| Best For | Photos, scanned docs, continuous tone images | Text, diagrams, technical drawings, logos |
| Transparency Support | ❌ Not supported | ✅ Full alpha channel |
| Text Quality | Good at high quality, artifacts at low quality | Perfect - no artifacts ever |
| Editing | Degrades with each save | No quality loss when re-saving |
| Typical Use | Email, web, general distribution | Archival, editing, professional work |
Choose JPG when: Converting scanned documents with photographs, creating files for email or web sharing, storage space is limited, slight quality loss is acceptable, distributing to general audiences, or dealing with continuous-tone images (photos, artwork). JPG compression reduces files to approximately 10% of uncompressed size, making it ideal for situations where file size matters more than perfect quality.
Choose PNG when: Converting documents with text and diagrams, preserving maximum quality is critical, transparency is needed, files will undergo further editing, creating archival copies, working with technical drawings or charts, or when lossless compression is required. PNG maintains pixel-perfect quality at approximately 30% of uncompressed size—larger than JPG but with zero quality loss.
| Page Size | Dimensions (inches) | At 150 DPI | At 300 DPI |
|---|---|---|---|
| US Letter | 8.5 × 11 | 1,275 × 1,650 px | 2,550 × 3,300 px |
| A4 (International) | 8.27 × 11.69 | 1,241 × 1,754 px | 2,481 × 3,508 px |
| Legal | 8.5 × 14 | 1,275 × 2,100 px | 2,550 × 4,200 px |
| Tabloid/Ledger | 11 × 17 | 1,650 × 2,550 px | 3,300 × 5,100 px |
| A3 | 11.69 × 16.54 | 1,754 × 2,481 px | 3,508 × 4,962 px |
| Executive | 7.25 × 10.5 | 1,088 × 1,575 px | 2,175 × 3,150 px |
| Use Case | Recommended DPI | Format | Rationale |
|---|---|---|---|
| Website Images | 72-150 DPI | JPG | Screens display ~96 DPI; higher wastes bandwidth |
| Email Attachments | 150 DPI | JPG | Balance quality with attachment size limits |
| Presentations (PowerPoint) | 150 DPI | JPG or PNG | Adequate for projection, manageable file size |
| Office Printing | 300 DPI | JPG | Standard print quality for documents |
| Professional Printing | 300 DPI | PNG | Maximum quality, no compression artifacts |
| Technical Drawings | 300-600 DPI | PNG | Preserve fine lines and text clarity |
| Legal Documents | 300-600 DPI | PNG | Preserve signatures and fine print |
| OCR (Text Extraction) | 300-600 DPI | PNG or JPG | OCR accuracy improves with higher DPI |
| Archival Storage | 600 DPI | PNG | Maximum preservation, no quality loss over time |
Example 1: Business Report for Email Distribution
Example 2: Technical Manual with Detailed Diagrams
Example 3: Legal Contract Archive
Example 4: Product Catalog for Website
Match DPI to Intended Use: Don't use 600 DPI for web-only documents—you're creating files 16x larger than necessary (600 DPI has 4x the pixels in each dimension). Conversely, don't use 72 DPI for documents that will be printed—quality will be unacceptable.
Format Selection by Content:
Batch Processing Planning: Use the calculator to estimate total storage requirements before batch converting large document collections. For example, 1,000 pages at 300 DPI JPG = approximately 1 GB total, while the same at 600 DPI PNG = approximately 8 GB.
Quality vs. Size Trade-offs: For most business documents, 150 DPI JPG provides the best balance. Files are small enough for easy sharing while maintaining adequate quality. Reserve higher DPI for documents that truly require it—printing, archival, or OCR.
Using Maximum DPI by Default: Many users assume "higher is always better" and convert everything at 600 DPI. This creates files 4x larger than 300 DPI with minimal quality benefit for most uses. Use appropriate DPI for intended purpose.
Using PNG for Everything: While PNG is lossless, its files are 3x larger than JPG. For photographs and scanned documents where perfect accuracy isn't critical, JPG saves substantial storage with imperceptible quality loss.
Ignoring Page Size: Converting A4 pages with US Letter settings (or vice versa) results in cropped or distorted images. Always verify page dimensions before conversion.
Not Planning for Storage: A project converting 5,000 pages at 600 DPI PNG could require 40-60 GB storage. Calculate storage needs in advance to avoid running out of space mid-project.
Converting Scanned PDFs at High DPI: If a PDF was created by scanning at 150 DPI, converting it to 600 DPI doesn't add detail—it just creates a larger file. Output DPI should match or exceed source DPI, but exceeding provides no benefit.
Megapixels (millions of pixels) indicate total image resolution. A higher megapixel count means more detail:
For context, a 4K display has 8.3 megapixels total. A single 300 DPI Letter-sized page contains enough pixels to fill an entire 4K screen at 100% zoom.
Use 72 DPI for web and screen display (smallest files, adequate for digital viewing), 150 DPI for general purpose including presentations and documentation (balanced quality and size), 300 DPI for high-quality printing and professional documents (industry standard for print), and 600 DPI for archival purposes, legal documents, or files requiring OCR text extraction (maximum quality, largest files). Higher DPI creates proportionally larger files but captures more detail.
Multiply page dimensions in inches by DPI to get pixel dimensions. Formula: Width (pixels) = Width (inches) × DPI, Height (pixels) = Height (inches) × DPI. Example: A standard 8.5×11 inch page at 150 DPI produces 1,275×1,650 pixels (2.1 megapixels). At 300 DPI, the same page becomes 2,550×3,300 pixels (8.4 megapixels). File size depends on format: JPG typically 10% of uncompressed size, PNG about 30%.
JPG uses lossy compression creating smaller files (approximately 10% of uncompressed size), ideal for photographs, scanned documents, and situations where file size is critical. Minor quality loss is usually imperceptible at medium to high quality settings. PNG uses lossless compression creating larger files (approximately 30% of uncompressed size), perfect for text documents, diagrams, technical drawings, and images requiring transparency. PNG preserves every pixel perfectly but at the cost of larger files.
High DPI settings create very large images. A letter-size page at 600 DPI produces a 5,100×6,600 pixel image (33.7 megapixels), equivalent to a high-end digital camera photo. This results in 8-12MB per page for JPG, 15-30MB for PNG. Solution: Reduce DPI to 150-300 for most uses (adequate quality at fraction of the size), choose JPG instead of PNG for photographs and scanned pages (50-70% smaller), or compress images after conversion.
Yes, enter any page dimensions in inches. Common standard sizes include US Letter (8.5×11), A4 (8.27×11.69), Legal (8.5×14), Tabloid/Ledger (11×17), A3 (11.69×16.54), and Executive (7.25×10.5). The calculator also works for custom sizes including posters, banners, business cards (3.5×2), postcards (6×4), and any non-standard dimensions. International paper sizes (A0-A10, B series) are fully supported.
DPI (dots per inch) directly determines image detail and clarity. Higher DPI captures more detail: 72 DPI shows basic content adequate for screens, 150 DPI provides good quality for most viewing, 300 DPI captures fine details suitable for professional printing, 600 DPI preserves maximum detail for archival and OCR. However, quality improvements diminish above 300 DPI for most uses. A 600 DPI image is 4x larger than 300 DPI (both dimensions doubled) but quality gain is often imperceptible unless zooming significantly.
PNG is superior for text-heavy PDFs because lossless compression preserves sharp text edges without artifacts. JPG's lossy compression creates slight blurring around text edges, making small fonts less readable. Use PNG at 150-300 DPI for documents with substantial text, diagrams, or technical drawings. For scanned documents that are already photographs of text, JPG is acceptable and creates much smaller files. If file size is critical, use JPG at high quality settings (85-95%) rather than low quality.
Yes, use the calculator to determine optimal settings, then apply those settings (DPI and format) to batch conversion tools. For example, calculate that 150 DPI JPG produces acceptable quality at 300KB per page, then batch convert 100 pages knowing you'll need approximately 30MB storage. The calculator helps you plan storage requirements, estimate processing time, verify settings before converting large batches, and choose appropriate quality settings for your specific use case.