About DisplayMath

A free screen size calculator that draws displays to scale, so a purchase is decided by the numbers rather than the marketing.

What it does

Enter a resolution and a diagonal, or pick a monitor, TV, laptop, tablet, phone or projector from the preset list, and DisplayMath works out the physical width and height, screen area, pixel density, aspect ratio, and how much of your view the screen fills from where you sit. Every display is drawn to scale on one canvas, so the difference between a 55-inch and a 65-inch TV, or a 27-inch monitor and a 34-inch ultrawide, is something you can see rather than estimate. On an iPhone, the TV size and mounting height pages can also measure your room in augmented reality and show a life-size screen on your wall.

The comparison pages answer the most common size questions in plain text, with the same to-scale drawing, for people who arrive from a search engine with one specific pair of screens in mind.

Where the numbers come from

Everything is derived from resolution, diagonal and, when you give one, viewing distance. Width and height follow from the diagonal and aspect ratio; pixel density is the diagonal resolution divided by the diagonal size; the viewing angle is the geometry of a screen of that width seen from that distance. Curved panels use their stated radius, so their chord, arc and field of view are the real ones.

Two references are used as guidance, not as rules. The 40-degree horizontal viewing angle is the cinema recommendation published in the THX viewing guide. The 60 pixels-per-degree figure is a common threshold for when individual pixels stop being resolvable at normal eyesight; it is a reference point, not a promise that two screens above it look identical. Sources are cited where a number appears.

Who makes it

DisplayMath is built and run by Alex Turbatu, an independent software developer based in Romania. It started as a spreadsheet for choosing a monitor and became a site once the drawing turned out to be more useful than the table. There is no company behind it and no team; questions and corrections go straight to the person who wrote the code, at hello@displaymath.com.

How the site pays for itself

DisplayMath is free, has no accounts and no paywall. Some pages show a single "See price" link for a screen that matches one of the presets, pointing to a search on Amazon or, for visitors in Romania, on eMAG. Those links are, or will be, affiliate links: when you buy something after following one, DisplayMath may earn a small commission from the store. The price you pay is the same either way, and the picks are chosen for being current and well reviewed, never for the commission. Where a link earns a commission the page says so beside it.

What DisplayMath does not do: sell your data, run advertising networks, or rank one screen above another because a store pays more. The privacy page describes exactly what the site collects, which is very little.

Editorial independence

No manufacturer or retailer has any say over the presets, the picks, the calculations or the comparison pages. Preset specifications are transcribed from manufacturer pages and corrected when readers report a mistake. If a store link ever influences a number on this site, that is a bug, and the address above is the place to report it.