DPI Resolution Converter
Convert between DPI (dots per inch), pixels per centimeter, and calculate total pixel dimensions for printing and display applications.
Enter DPI and physical size to calculate pixel dimensions, or enter pixels and DPI to find print size.
8×10 inches at 300 DPI = 2400×3000 pixels (7.2 MP)
Understanding DPI and Resolution
DPI (dots per inch) and PPI (pixels per inch) are measures of resolution that describe how many dots or pixels fit within one inch of an image or print. While technically different (DPI refers to printer output, PPI to screen display), the terms are often used interchangeably in casual usage. Higher values mean finer detail and sharper images.
Core Conversion Formulas:
- DPI to dots per cm:
dots/cm = DPI / 2.54 - Dots per cm to DPI:
DPI = dots/cm × 2.54 - Total pixels:
pixels = DPI × size in inches - Print size from pixels:
inches = pixels / DPI
Standard DPI Values by Application:
| Application | Typical DPI | Notes |
|---|---|---|
| Web/screen display | 72-96 DPI | Standard screen resolution |
| Retina/HiDPI screens | 144-326 DPI | Apple Retina and similar |
| Office printing | 150-200 DPI | Adequate for text and charts |
| Quality photo printing | 300 DPI | Standard for professional prints |
| High-end art printing | 600 DPI | Museum-quality reproduction |
| Commercial printing | 300-1200 DPI | Magazines, brochures |
| Large format/banners | 72-150 DPI | Viewed from a distance |
Image Size at Different DPI (for an 8×10 inch print):
| DPI | Total Pixels (Width × Height) | File Size (approx., 24-bit) |
|---|---|---|
| 72 | 576 × 720 | 1.2 MB |
| 150 | 1,200 × 1,500 | 5.1 MB |
| 300 | 2,400 × 3,000 | 20.6 MB |
| 600 | 4,800 × 6,000 | 82.4 MB |
Practical Examples:
- A 4000 × 3000 pixel photo printed at 300 DPI produces a print of 13.3 × 10 inches (33.8 × 25.4 cm). The same image at 150 DPI would print at 26.7 × 20 inches (67.7 × 50.8 cm) but with less detail.
- A website banner that is 1920 × 400 pixels displayed at 96 PPI appears as 20 × 4.17 inches on screen.
- Scanning a document at 300 DPI means a standard letter-size page (8.5 × 11 inches) produces an image of 2,550 × 3,300 pixels.
- A billboard measuring 14 × 48 feet only needs 10-20 DPI because it is viewed from far away, resulting in a manageable file of about 1,680 × 5,760 pixels at 10 DPI.
Tips:
- For printing photos at home, 300 DPI is the gold standard. Below 200 DPI, individual pixels become visible to the naked eye.
- Increasing DPI in image software (upsampling) does not add real detail. It just interpolates between existing pixels.
- When scanning old photos, use at least 600 DPI to capture fine details and allow for future cropping or enlargement.
- Screen resolution (PPI) varies by device: typical monitors are 96-110 PPI, smartphones are 300-500+ PPI, and some professional displays reach 218 PPI.