Measure the screen, plan the desk — before you buy. Type a diagonal and pick a resolution, and Monitor Math returns the real width, height, screen area, and pixel density in inches and cm, draws it to scale, and checks how it fits your desk.
Monitor Math is strongest when the calculator and setup planner answer the practical question first. These are the routes worth crawling and using before the long tail of generated comparisons.
Jump straight to practical monitor comparisons: 27-inch vs 32-inch, first ultrawide jumps, 38/40/45/49-inch desk trade-offs, and setup layouts you can adjust in the builder.
Quick visual checks for the questions that are hard to judge from diagonal size alone: physical screen shape, desk span, and how wide resolutions compare with 4K.
A monitor's advertised size is its diagonal, but the useful numbers are width and height. Split the diagonal by the aspect ratio: width = diagonal × ratioW ÷ √(ratioW² + ratioH²), and height = diagonal × ratioH ÷ √(ratioW² + ratioH²). This calculator does it automatically — enter a diagonal and aspect ratio to get exact width, height, screen area, and pixel density in inches and centimeters.
What are the dimensions of a 27-inch monitor?
A 27-inch 16:9 monitor is about 23.5 inches wide and 13.2 inches tall (59.8 × 33.6 cm), roughly 312 square inches of screen. Width and height depend on the aspect ratio, so a 27-inch 16:9 and a 27-inch ultrawide are not the same shape at the same diagonal.
How do I find monitor width and height from the diagonal?
Use the aspect ratio. For a 16:9 screen, width ≈ diagonal × 0.872 and height ≈ diagonal × 0.490. For other shapes (16:10, 21:9, 32:9, 3:2), the exact ratio changes those multipliers — the calculator applies the precise formula for any aspect ratio you enter.
What is PPI and how do I calculate it?
PPI (pixels per inch) measures sharpness: PPI = √(widthPx² + heightPx²) ÷ diagonal. A 27-inch 1440p panel is about 109 PPI, while a 27-inch 4K panel is about 163 PPI. Use the dedicated PPI calculator at /ppi-calculator for any size and resolution.
Do two monitors of the same size have the same dimensions?
Only if they share an aspect ratio. A 34-inch 21:9 ultrawide is far wider and shorter than a 34-inch 16:9 monitor. Aspect ratio changes both width and height even at an identical diagonal, which is why the calculator asks for the shape as well as the size. The aspect ratio calculator at /aspect-ratio-calculator shows the difference.
