CalcKit
Image Resolution Converter
Image resolution is how many dots or pixels fit in a length of print or screen: dots per inch (dpi) for printers, pixels per inch (ppi) for images and screens, and dots per millimeter (dpmm) for label and industrial printers. The more per inch, the finer the detail.
Photos are usually printed at 300 dpi, and posters seen from a distance at 150 dpi or less. Thermal label printers come in 203 dpi (8 dpmm) and 300 dpi (12 dpmm).
How to convert dpi
Type a value into any field, and every other unit is calculated at once. An inch is 25.4 mm, so:
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dpi to dpmm: divide by 25.4.
300 / 25.4 = 11.81 dpmm -
dpmm to dpi: multiply by 25.4.
8 × 25.4 = 203.2 dpi
Dpi and ppi are the same number: both count per inch, dots on paper and pixels in a file.
Print size from pixels
To find how large an image prints, divide its pixels by the resolution. A photo 3,000 pixels wide at 300 dpi prints 3,000 / 300 = 10 inches wide, which is 25.4 cm.
Common conversions
| Value | Equals |
|---|---|
| 1 dpi | 0.0393701 dpmm |
| 1 dpmm | 25.4 dpi |
| 300 dpi | 11.81 dpmm |
| 1 dpi | 39.3701 dpm |
Units of image resolution
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Dot per meter (dpm): Dots per meter is a unit of image resolution that measures the number of dots or pixels per linear meter. It is commonly used in the printing industry to determine the print quality. The higher the dpm value, the finer the detail in the printed image.
Conversion Factor: 1 dpm = 0.001 dpmm = 0.0254 dpi = 0.0254 ppi -
Dot per millimeter (dpmm): Dots per millimeter is a unit of image resolution that measures the number of dots or pixels per linear millimeter. It is often used in industrial printing and high-resolution imaging applications.
Conversion Factor: 1 dpmm = 1000 dpm = 25.4 dpi = 25.4 ppi -
Dot per inch (dpi): Dots per inch is a common unit of image resolution used in both digital and print media. It indicates the number of dots or pixels per linear inch. Higher dpi values result in finer details and smoother images.
Conversion Factor: 1 dpi = 39.37 dpm = 0.03937 dpmm = 1 ppi -
Pixel per inch (ppi): Pixels per inch is a unit of image resolution that denotes the number of pixels per linear inch. It is equivalent to dots per inch and is primarily used in digital imaging and display devices such as computer monitors, smartphones, and tablets. Higher ppi values indicate greater image detail and sharpness.
Conversion Factor: 1 ppi = 39.37 dpm = 0.03937 dpmm = 1 dpi