JPEG (JPG)

JPEG stores width and height in pixels. Application and encoder limits vary, so check the actual tool and recipient. Calculate output size from pixels and the required effective pixel density.

For any intended print, calculate effective density in both directions after cropping. If the aspect ratio does not match the target, either crop, letterbox, or redesign deliberately; nonuniform stretching distorts the photograph. Also check practical file-size and pixel limits in the specific application, because the standard is not a guarantee of available memory or upload acceptance.