Digital Image Resolution Converter
Convert digital image resolution (pixel or dot density) between per inch, per centimeter, per millimeter, per meter and per foot. Pick any two units for an exact result.
Digital Image Resolution Formula
Digital image resolution here means density: how many pixels (or dots) fit into one unit of length. Because the inch is exactly 2.54 cm, 25.4 mm and 0.0254 m, converting only needs those exact length ratios. A longer length unit holds more pixels, so a value per centimeter is smaller than the same density per inch. This tool does not change the pixel dimensions or file size of an image, and it treats one dot as one pixel (1 dpi = 1 ppi), as is usual for digital images.
What Is Digital Image Resolution?
When people say resolution for printing or scanning, they usually mean pixel density: the number of pixels or dots along one unit of length. The most common unit is pixels per inch (ppi). Printers and scanners often say dots per inch (dpi) for the same idea. Many countries that use the metric system prefer pixels per centimeter (ppcm) or per millimeter (ppmm), and some technical documents use pixels per meter (ppm), as stored in PNG and BMP files.
Density is different from image dimensions and file size. An image that is 3000 × 2000 pixels has those dimensions whatever its density. Density only tells you how large it will be when printed: pixels ÷ density = printed length. For example, 3000 pixels at 300 ppi prints 10 inches wide. Resolution does not describe file size in megabytes either, because that also depends on compression and color depth.
If you need to convert plain lengths such as inches to centimeters, see the Inches to CM Converter.
Supported Digital Image Resolution Units
Every unit below is converted through exact length ratios (1 inch = 2.54 cm = 25.4 mm = 0.0254 m, 1 ft = 12 in).
| Unit | Symbol | 1 unit equals (in ppi) | Basis |
|---|---|---|---|
| Pixels per inch | ppi | 1 ppi | Reference unit |
| Dots per inch | dpi | 1 ppi | 1 dpi = 1 ppi |
| Pixels per centimeter | ppcm | 2.54 ppi | Exact (2.54 ppi) |
| Dots per centimeter | dpcm | 2.54 ppi | Exact (2.54 dpi) |
| Pixels per millimeter | ppmm | 25.4 ppi | Exact (25.4 ppi) |
| Dots per millimeter | dpmm | 25.4 ppi | Exact (25.4 dpi) |
| Pixels per meter | ppm | 0.0254 ppi | Exact (0.0254 ppi) |
| Dots per meter | dpm | 0.0254 ppi | Exact (0.0254 dpi) |
| Pixels per foot | ppf | 0.0833333333333 ppi | Exact (1 ÷ 12 ppi) |
| Dots per foot | dpf | 0.0833333333333 ppi | Exact (1 ÷ 12 dpi) |
How to Use the Digital Image Resolution Converter
- Type the resolution value, such as 300 or 118.11, into the input box.
- Choose the unit to convert from and the unit to convert to.
- The converted resolution appears at once, along with the value in all the other units. You can also press Convert Now.
- Use Swap Units to reverse the conversion, Copy Result to copy the answer, or Reset to clear.
Resolution must be zero or positive. To find a print size, divide the number of pixels by the resolution in the unit you want, for example pixels ÷ ppi = inches.
Practical Examples
- Print quality: 300 ppi = 118.11023622 pixels per centimeter.
- Web and screen: a 96 ppi display setting equals 3.77952755906 pixels per millimeter.
- Metric to inch: 118 ppcm = 118 × 2.54 = 299.72 ppi.
- PNG metadata: 11,811 pixels per meter is about 299.9994 ppi.
- Large format: 150 ppi = 1,800 pixels per foot.
Digital Image Resolution – Common Values
Quick reference for frequently used conversions
| Pixels/inch (ppi) | Pixels/cm (ppcm) | Pixels/mm (ppmm) | Pixels/meter (ppm) | Pixels/foot (ppf) |
|---|---|---|---|---|
| 72 | 28.3464566929 | 2.83464566929 | 2,834.64566929 | 864 |
| 96 | 37.7952755906 | 3.77952755906 | 3,779.52755906 | 1,152 |
| 150 | 59.0551181102 | 5.90551181102 | 5,905.51181102 | 1,800 |
| 200 | 78.7401574803 | 7.87401574803 | 7,874.01574803 | 2,400 |
| 254 | 100 | 10 | 10,000 | 3,048 |
| 300 | 118.11023622 | 11.811023622 | 11,811.023622 | 3,600 |
| 600 | 236.220472441 | 23.6220472441 | 23,622.0472441 | 7,200 |
| 1,200 | 472.440944882 | 47.2440944882 | 47,244.0944882 | 14,400 |
Real-Life Applications of Resolution Conversion
- Printing: print shops, magazines and photo labs state requirements in dpi, ppi or ppcm. Common targets are 150 to 300 ppi for photos.
- Scanning: scanner settings are in dpi, while file metadata may store pixels per meter or per centimeter.
- Screen design: pixel density of monitors and phones is quoted in ppi, while hardware data sheets may use ppmm.
- Image file metadata: PNG and BMP files record physical density in pixels per meter, so conversion is needed to read it as ppi.
- Large-format and signage: large prints use lower density, which may be given per foot or per meter.
- Medical and industrial imaging: sensors and specifications can be written in pixels per millimeter.