Reference & information
Sources & reference notes
Primary references for definitions and implementation behavior.
Checked on 2026-09-28. Sources support the limited facts described below. They do not endorse this site. Competitor pages informed product research only; their copy, images and code are not part of this website.
LilyPond · Predefined paper sizes ↗
Typesetting reference for nominal A, ISO B, C envelope, US, ANSI and architectural dimensions. We retain the defining millimeter or inch column and calculate conversions independently. ISO B is not JIS B.
MDN · CSS length values ↗
Definitions of CSS absolute, font-relative and viewport-relative length units. em depends on the property context; vw and vh use the large viewport.
NIST · SI units: length ↗
The inch is exactly 25.4 millimeters. All inch/metric conversions use this definition.
Adobe · Printed image resolution ↗
Image resolution in pixels per inch and the distinction between pixel dimensions and physical print dimensions.
Adobe · Printer resolution ↗
Printer dot resolution is a different quantity from the image pixel density supplied to the printer.
Canon · Available paper sizes ↗
Nominal A3, A4 and A5 dimensions in millimeters and US paper dimensions in inches. This is a size reference, not a compatibility claim for your printer.
W3C · CSS units ↗
The fixed relationship between CSS absolute units, including 96 CSS pixels per CSS inch. These units do not measure a screen’s physical pixel density.
MDN · createImageBitmap ↗
Browser decoding of a local image, including image orientation. No image is sent to an image-analysis service.
Original material
The geometric formulas, worked examples, explanatory text and SVG diagrams are created for this project. Standard paper dimensions are factual reference values. Named photo sizes are explicit inch dimensions. No third-party photographs are bundled. Visitor-selected image previews belong to their respective owners and remain local.