PJHTech ImagesHow to calculate an image's print size
Divide each pixel dimension by the intended pixels per inch. The results are the width and height in inches.
Worked example
A 3600 × 2400 image at 300 PPI gives a 12 × 8-inch print. Multiply the inch values by 25.4 to get 304.8 × 203.2 mm.
| Calculation | Formula |
|---|---|
| Print width in inches | Pixel width ÷ PPI |
| Print height in inches | Pixel height ÷ PPI |
| Millimeters | Inches × 25.4 |
| Required pixels | Inches × PPI |
Calculate after cropping
A 3600 × 2400 image cropped to a square may leave 2400 × 2400 pixels. At the same 300 PPI, that square is 8 × 8 inches. Use the remaining dimensions, not the original ones.
The calculation describes pixel density. It does not measure focus, motion blur or the quality of the original capture.
Open the print size calculator
Related guides
- Photo print size table
- What is an image aspect ratio?
- Why does a print cut off part of my photo?
- Image pixels and resolution, explained