Print size calculator
Pixels to MM for Printing
See how large an image can print at a chosen resolution. Compare common print DPIs, preserve the aspect ratio, and get the finished dimensions in millimeters and inches.
Live conversion
Enter dimensions
Converted size
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mm = pixels × 25.4 ÷ DPI Enter valid dimensions to see the calculation.
Calculations stay in your browser. No dimensions are uploaded.
Three-step workflow
How to use this calculator
Find the image dimensions
Read the image width and height in pixels from file properties or your editor.
Choose the output DPI
Use the density requested by your printer or print service; 300 DPI is a common high-quality target.
Use the calculated size
Set the document or print frame to the returned millimeters without resampling the source image.
Practical guide
Match pixel dimensions to the intended print size
Print size depends on both pixel count and output density. A 3000-pixel-wide image prints 254 mm wide at 300 DPI, but 508 mm wide at 150 DPI. The pixel data is unchanged; only the physical scale differs.
If you enlarge beyond the calculated size while keeping the same pixels, the effective DPI falls. That can be acceptable for posters viewed from farther away, while small photos and detailed documents usually benefit from a higher effective resolution.
Common questions
For Printing FAQ
How many pixels are needed for 100 mm at 300 DPI?
About 1,181.1 pixels, so use at least 1,182 pixels when an integer dimension is required.
Is 300 DPI always required for printing?
No. It is a common high-quality target, but viewing distance, print process, substrate, and printer requirements can justify other values.
Does changing DPI add image detail?
Changing only DPI metadata does not add pixels. Resampling can add pixels, but it cannot recreate original captured detail.
Should bleed be included in the pixel size?
Yes, when the printer requires bleed, calculate the full artwork dimensions including the bleed area.
Specialized tools
More pixel-to-mm tools
Continue with a calculator tailored to another design, print, or office workflow.