Screen Size Calculator

Screen size is measured along the diagonal, but what you actually see is the area, which scales with the square of the diagonal. A 32-inch 16:9 monitor is roughly four times the area of a 16-inch one, not twice. This is the most common mistake when people compare screens. Doubling the diagonal quadruples the surface area, which is why upgrading from a 24-inch to a 27-inch feels like more of a jump than the numbers suggest.

The calculator works backwards from diagonal and aspect ratio to give you actual width and height in inches and centimetres, plus the visible area. For a 27-inch 16:9 monitor: width 23.53 inches, height 13.24 inches, area 311.6 square inches. A 32-inch 16:9 is 27.89 × 15.69 inches, area 437.6 square inches; about 40% larger, not 18%.

Two screens with the same diagonal but different aspect ratios are very different. A 34-inch 21:9 ultrawide and a 34-inch 16:9 monitor share a diagonal but the ultrawide is wider and shorter; the 16:9 is taller. For desk gaming, the ultrawide gives a more immersive horizontal field of view. For coding or document work, a 16:10 (more vertical pixels for the same diagonal) often beats 16:9 because you can see more lines of code or text without scrolling.

TVs are almost always 16:9, so cross-comparisons are straightforward. Laptop screens vary: 16:9 is common, 16:10 is making a comeback, and Apple's 14-inch and 16-inch MacBooks use a slightly taller ratio. The [Aspect Ratio Calculator](/aspect-ratio-calculator) is the right tool when you want to find the third number from a known ratio (e.g. how tall a 1920px wide image is at 16:9).