Core conversions
One inch equals exactly 25.4 millimetres. Pixels required equals physical inches multiplied by the selected PPI. Physical print inches equals pixels divided by PPI.
All displayed pixel dimensions are rounded to the nearest whole pixel only after calculation from the stored physical measurement. Pixel inputs are restricted to positive whole numbers; physical sizes and PPI must also be positive.
Effective PPI for a filled print
Horizontal PPI equals pixel width divided by printed width in inches. Vertical PPI uses height. For a fill-to-size result, the lower value is reported because it is the limiting dimension.
Quality labels
Meets target allows a 0.1% tolerance for unavoidable whole-pixel rounding. Close to target means at least 80% of the chosen target; Limited means at least 50%. These labels compare numbers and do not certify a print process.
Crop percentage
The crop estimate compares source and target aspect ratios. It reports the image-area fraction retained by a centered fill crop. Manual crop position changes which content is removed, not the calculated area fraction.