Art and Design: DPI, PPI, Pixel Dimensions, and Print Resolution Conversions
Published April 24, 2026
Designers convert between pixels (screen), inches (print), centimeters (international), DPI (dots per inch), and PPI (pixels per inch) constantly. A 1920×1080 pixel web image at 96 PPI is 20"×11.25"—but print-quality requires 300 DPI, tripling resolution. Misunderstanding these conversions results in pixelated prints, oversized canvas specifications, or wasted assets.
Table of Contents
Understanding the Basics
DPI (dots per inch, print) and PPI (pixels per inch, screen) are often conflated. 72 PPI (old web standard) = 72 pixels per inch on screen; 300 DPI (print standard) = 300 ink dots per inch on paper. A 1920-pixel-wide screen image at 96 PPI = 20 inches at 72 DPI ≈ 6.4 inches at 300 DPI. To print 1920×1080 at 300 DPI, multiply: 1920 × 300 ÷ 72 = 8000 pixels wide.
Canvas size and image resolution interact: 1000 × 1000 pixels at 72 PPI = 13.9" × 13.9". Same 1000 × 1000 pixels at 300 PPI = 3.3" × 3.3". Designers must choose: shrink the physical dimensions or enlarge the pixel count (upscaling loses quality). "Pixels per inch" is metadata; changing it without changing pixel dimensions just scales the print output.
Design Resolution Units
- Pixels (px): Screen unit. No physical size until tied to PPI.
- Points (pt): 1/72 inch. Typography standard. 72 pt = 1 inch.
- Inches (in) & Centimeters (cm): Physical print dimensions. 1 inch = 2.54 cm.
- PPI (Pixels Per Inch): Screen resolution. 96 PPI (Windows), 72 PPI (Mac legacy), 326 PPI (iPhone Retina).
- DPI (Dots Per Inch): Print resolution. 72 DPI (web), 150 DPI (acceptable print), 300 DPI (photo quality).
Conversion Table
| from | to | factor |
|---|---|---|
| Pixels × PPI | Inches | Inches = Pixels ÷ PPI |
| Inches | Centimeters | × 2.54 |
| Web image (72 PPI) | Print image (300 DPI) | × 4.17 pixels (300÷72) |
| Points (pt) | Pixels (px) | × 1.33 at 96 PPI |
Worked Examples
Print Resolution Mismatch
1920×1080 web image at 72 PPI = 26.7"×15" print size. Too large at low DPI—pixelated. To print at 300 DPI same size: 1920 × (300÷72) = 8000 pixels wide. Resize in Photoshop/Figma to 8000×4500 pixels, then print at 300 DPI, 26.7"×15".
Social Media Canvas Specs
Instagram feed post: 1080×1080 pixels at 72 PPI (web standard). Print that image: 15"×15" at 72 DPI—low quality. For print version, upsample or re-create at 1080 × (300÷72) = 4500×4500 pixels.
Practical Applications
Web design: 72 or 96 PPI. Pixel dimensions define layout. Images ≈100 KB after compression.
Print design: 300 DPI standard. If starting from web, multiply pixel dimensions by 300÷72 = 4.17. Expect 10-50 MB files.
Social media: Platform-specific pixel dimensions (Instagram 1080×1080, Twitter 16:9 aspect). Don't rely on metadata; pixel dimensions are all that matter.
Typography: Point size (pt) traditionally = 1/72 inch. 72 pt text = 1 inch tall on screen at 96 PPI. Print text scales differently depending on DPI.
Best Practices
💡 Never change DPI/PPI without resizing pixel dimensions. "72 to 300 DPI" metadata change does not improve print quality—you must increase pixels. Use resampling in Photoshop (Image → Image Size, resample ON).
Never change DPI/PPI without resizing pixel dimensions. "72 to 300 DPI" metadata change does not improve print quality—you must increase pixels. Use resampling in Photoshop (Image → Image Size, resample ON).
Common Mistakes
⚠️ Upscaling (increasing pixels without new data) reduces quality. If a 1920-pixel image must print at 300 DPI, avoid upscaling beyond 2×. Better to re-create at higher resolution than upscale degraded files.
Upscaling (increasing pixels without new data) reduces quality. If a 1920-pixel image must print at 300 DPI, avoid upscaling beyond 2×. Better to re-create at higher resolution than upscale degraded files.
Tools and Resources
- DPI/PPI calculator: Input pixels, get print size for any DPI
- Photoshop Image Size dialog: Visual tool for resampling and DPI changes
- Online resolution converter: Quick pixel-to-inch conversions for any PPI
Key Takeaways
- PPI = pixels per inch (screen); DPI = dots per inch (print). 96 PPI (web), 300 DPI (photo print).
- Physical print size = pixels ÷ DPI. To print 1920 pixels at 300 DPI: 1920 ÷ 300 = 6.4 inches.
- To resize web image (72 PPI) for print (300 DPI): multiply pixels by 300÷72 = 4.17.
- Changing DPI metadata without resampling pixels doesn't improve quality—always resample.
- Social media: ignore DPI; focus on pixel dimensions (1080×1080, 1200×628, etc.). Platforms scale for you.