About ScreenSize

ScreenSize turns the one number screens are sold by — the diagonal — into the numbers people actually need: real width and height, pixel density and dot pitch.

Why it exists

“55-inch” describes no side of a TV. Furniture, wall mounts, desk depth, monitor arms, sleeves and flight cases are all bought against widths and heights, and sharpness is judged by density, not by the diagonal at all. The calculators here do the small amount of geometry — Pythagoras, three ways — carefully and in the open, with the formulas published on the how-to page so any result can be checked by hand.

Where the device numbers come from

Device tables on this site use specifications published by the manufacturers themselves — panel diagonal, native resolution and, where listed, PPI — and only include models we could verify against those spec pages at the time of writing. Specifications change between regions and revisions, so the tables carry a standing reminder to check the maker's current sheet before buying. Market-context numbers, such as comfortable viewing distances, are labelled as rules of thumb wherever they appear.

Part of a small tool family

ScreenSize is one of a group of single-purpose, browser-based tools. Its closest sibling works the same geometry for images rather than panels: the aspect ratio calculator at AspectRatio. The rest of the family is linked in the footer of every page.

Limits

• Dimensions are the viewable picture, not the product. Bezel, stand and VESA hardware are model-specific.
• PPI assumes square pixels, which holds for modern LCD and OLED panels; a few specialist panels (some PenTile layouts) render subpixels differently.
• Nothing here is a buying recommendation — it is arithmetic plus published specifications, presented so you can decide.