Screen & print planning
Image Resolution Calculator
Compare what your current pixel dimensions produce at a chosen DPI with the pixels required for a target physical size.
Image Resolution Calculator
Compare existing pixel dimensions with physical print targets at a chosen DPI.
What the resolution calculator shows
Useful for
- Photo and artwork printing
- Document scan planning
- Marketplace and publishing specifications
- Checking whether enlargement is necessary
How to calculate image resolution
- 1
Enter current pixels
Use the source image width and height.
- 2
Enter the target DPI
Use the density required by your output destination.
- 3
Enter the physical target
Add the desired width and height in millimetres.
- 4
Compare current and required values
Use the result to decide whether cropping, resizing or a different source is needed.
Formula and limits
- • Physical millimetres = pixels ÷ DPI × 25.4.
- • Required pixels = millimetres ÷ 25.4 × DPI.
- • Upscaling can add pixels but cannot recreate source detail with ordinary interpolation.
- • Always check the final file against the destination requirement.
Resolution has a source side and an output side
The source side is the number of pixels already present. The output side is how densely those pixels are placed when printed.
Keeping both values visible prevents a common mistake: assuming a higher DPI metadata value automatically creates a higher-resolution image.
Frequently asked questions
How large can I print an image at 300 DPI?
Divide each pixel dimension by 300 to get inches, then multiply by 25.4 for millimetres.
Can I increase resolution without losing quality?
Downscaling can preserve good quality, but enlarging beyond the source detail requires interpolation and may soften the image.
What resolution should I use for print?
Use the value required by the printer or publisher. 300 DPI is common for many photo workflows but is not a universal rule.
Does screen resolution use DPI?
Screens are primarily described by pixel dimensions and device pixel density. DPI becomes most practical here for physical-size planning.
Related image tools
Inspect dimensions, file size, format, aspect ratio and megapixels from an image.
Read an image ratio and calculate matching dimensions without stretching.
Create a new image at the pixel dimensions required by your destination.
Reduce encoded file size after you have chosen the right dimensions.