Print Size and DPI Calculator: Pixels to Inches
Enter an image’s pixel dimensions and a chosen PPI to calculate its physical print size. You can also check effective PPI at a target width. This tool uses numbers only: it does not inspect, upload, sharpen or enlarge the image itself.
Calculate print size and effective PPI
Worked example: 3,000 × 2,400 pixels
At 300 PPI, width is 3,000 ÷ 300 = 10 inches and height is 2,400 ÷ 300 = 8 inches. That is 254 × 203.2 mm.
At a target width of 15 inches, the unchanged 5:4 image ratio gives 12 inches height. Effective resolution becomes 3,000 ÷ 15 = 200 PPI. The calculator preserves the ratio; it does not crop to a frame.
PPI and printer DPI are different
PPI describes how many image pixels occupy one inch at a chosen output size. Printer DPI describes device dot placement. A printer can use multiple dots to represent an image pixel, so its advertised 1,200 DPI is not a substitute for the photo’s actual pixel dimensions. This page uses the common search term DPI calculator, but its calculations concern image PPI.
Use the result without a false quality promise
Read the original pixel dimensions in your image editor or file information. Enter them in the intended orientation, choose a PPI and compare the result with the physical print you need. The default 300 PPI is a useful calculation starting point, not a pass/fail quality threshold for every subject, medium and viewing distance.
A blurred, heavily compressed or poorly exposed image can print poorly despite a high calculated PPI. A large print viewed from farther away may tolerate a lower value. For an important job, print a representative section at the intended scale and judge it under the intended viewing conditions.
Formulas and cropping
- Print width in inches = pixel width ÷ chosen PPI.
- Print height in inches = pixel height ÷ chosen PPI.
- Effective PPI at a target width = pixel width ÷ target width in inches.
- Target height = target width × pixel height ÷ pixel width.
- Multiply inches by 25.4 to get millimetres.
Cropping removes pixels. Recalculate from the cropped dimensions rather than the original file. Changing a resolution metadata field does not add pixels. Resampling can create additional pixels, but it does not guarantee recovery of missing scene detail.
Sources and next steps
Adobe’s print-resolution guidance explains the relationship between output and image detail. Compare print and frame ratios, follow the 4 × 6 crop example, or use the blurry-PDF checklist when the source and printed result differ.