About
About SizeChart
SizeChart is an independent reference site for standard sizes and unit conversion. It is built for people who need a quick, reliable answer before buying paper, printing a photo, choosing a screen, furnishing a room, or converting land and length units.
What we publish
The site has two parts. Standard sizes covers paper, photo, screen, print, clothing, furniture and sports dimensions. Unit conversion covers length and area, including metric, imperial, Chinese market units and nautical or astronomical units where relevant.
Every chart shows the same measurement in millimetres, centimetres, inches and pixels where a pixel value is meaningful. The goal is to make a size usable at the point of decision, not to collect as many numbers as possible.
Where the data comes from
Paper sizes follow ISO 216 and the common Chinese K-sheet conventions. Photo and ID requirements are compiled from published government, embassy and visa-centre specifications. Screen dimensions are calculated from the advertised diagonal and aspect ratio. Clothing charts are compiled from publicly published brand and retailer size tables, then rounded into comparable ranges.
Standards change and brands revise their charts. We therefore treat each table as a reference, not as a guarantee, and we link the relevant standard or measurement logic wherever possible.
How we check the numbers
Dimensions are stored once in a structured data file, then converted by the same code path used by the public calculator. This reduces the chance that a millimetre value and its inch equivalent disagree. Pages are rebuilt after a data correction so that the table, the converter and the search description stay in sync.
Independence and corrections
SizeChart is not affiliated with a paper manufacturer, retailer or brand. There are no sponsored size rankings. If a value is wrong, outdated or ambiguous, send the page URL, the value you expected and a public source if you have one. Corrections are reviewed before the data file is changed.