Methodology
Source dimensions
Each record stores its original width and height in millimeters, plus a named source. ISO A dimensions come from the ISO 216 family; US and ANSI sizes use documented nominal dimensions. Photo formats are nominal print sizes and can vary by product or trim.
Calculated values
Centimeters, inches, points, area, aspect ratio and pixels are calculated from those stored millimeter values. One inch equals exactly 25.4 millimeters. Pixel count is millimeters ÷ 25.4 × DPI, rounded to the nearest integer for each axis.
Rounding and use
Displayed inches usually use two decimal places while calculations retain full precision. A one-pixel difference can occur when another tool rounds an intermediate inch value first. Effective resolution is an arithmetic result, not a guarantee of print quality. AI is not used as a source for numerical dimensions or at runtime.