Resolution converter

Resolution converter is the tool on this page. The control sits above this text. Use it on the display you want to judge, then read what the result can and cannot mean. The target phrase people search is tied to this job, and the explanation below stays with that job instead of repeating a generic review of every display ever made.

Every calculator on this shelf uses a short formula and shows the result in inches and centimetres when both make sense. PPI is the diagonal in pixels divided by the diagonal in inches. The pixel diagonal is the square root of width squared plus height squared. DPI on a printer is dots of ink. People search DPI when they mean PPI. The DPI page uses the display formula and says so, because treating them as one word causes bad print files and confused monitor shopping.

Physical size comes from the diagonal and the aspect ratio. A 27-inch 16:9 panel is not 27 inches wide. The width is 27 times 16 divided by the diagonal of a 16 by 9 rectangle, about 23.5 inches. Height is about 13.2. Area is width times height. Two 24-inch screens do not equal one 48-inch screen. The area grows with the square of the diagonal only when the aspect ratio stays the same.

Megapixels are width times height divided by one million. A 4K frame, 3840×2160, is about 8.3 megapixels. That number describes the image, not the sharpness at your eye. Sharpness at the eye is PPI and viewing distance together. A phone can be sharper than a television and still hold fewer pixels. The density comparison page puts two displays side by side for that reason.

Aspect ratio is the fraction of width and height after you remove the common factor. 1920×1080 and 3840×2160 are both 16:9. 3440×1440 is 43:18, close to 21:9. 1968×2184, the Galaxy Z Fold 7 inner panel, is nearly square. A calculator that only says 16:9 forever is useless the moment you open a foldable or an ultrawide.

Screenz is a set of pictures and arithmetic for the display you already have. The picture is drawn by the browser. The arithmetic is the same formula a spec sheet uses, written out so you can change the inputs. Neither one is a laboratory certificate. A dead pixel you can see is real. A refresh number that does not match the sticker is a clue about the operating system, the cable, the battery mode, or the browser, not an automatic failure of the panel.

Use fullscreen when you are hunting a mark. The address bar, the notch, and the rounded corner all hide the edge, and the edge is where a bad pixel and a fold crease like to sit. On a phone, turn the brightness up and turn off the reading tint. On a monitor, leave the preset you actually use, then repeat the test in the neutral preset if you are judging color. Night shift, f.lux, and vivid modes are fine for the evening and misleading for a test.

Dust sits on the glass and moves when you tilt the panel. A dead subpixel stays dark. A stuck subpixel stays lit, so it shows on black. A crease on a foldable is a hinge in the stack. It is not a dead pixel, and a flat color shows it more honestly than a photograph. Pressure spots and backlight bleed on an LCD change with the angle of your head. OLED black should look off, except at the camera hole and along a fold.

The browser cannot measure nits, cannot read EDID on most pages, and cannot promise that a 10-bit ramp is being sent as 10-bit. If a gradient shows steps, the steps may be the panel, the operating system, or the compositor. If a refresh counter reads 60 on a 144 Hz monitor, check the cable, the power plan, and the display setting before you blame the page. Screenz will say this again because it is the difference between a useful test and a false warranty claim.

Photographing the panel with a second phone adds moiré and makes uniformity look worse than it is. Trust your eye at the distance you actually sit. Move closer only to confirm that a mark is in the pixels rather than on the glass. Then wipe the glass and look again. A foldable should be checked twice, cover display and inner display, because they are different diagonals, different pixel densities, and often different aspect ratios.