Screen Size Calculator
A screen’s advertised size is its diagonal, measured corner to corner. This works out its actual width and height.
Screen
A screen’s advertised size — 27 in, 55 in — is the diagonal, measured corner to corner. Enter it with the screen’s shape to get the real width and height.
Common diagonals
Aspect ratio describes the shape of a screen: how wide it is for its height. 16:9 is standard widescreen; 21:9 is ultrawide.
Common aspect ratios
Screen resolution (optional)
Optional — add the screen resolution if you also want pixel-density information. Resolution is how many pixels the screen shows across and down, such as 2560 × 1440.
With a resolution, this tool also reports pixel density — how tightly the pixels are packed.
Display area
23.53 × 13.24in
A screen sold as 27 in measures that corner to corner. Its picture area is 23.53 in across and 13.24 in tall at 16:9. That is 59.77 × 33.62 cm.
Display area 23.53 by 13.24 in.
Display shape
Details
- Width23.53 in59.77 cm
- Height13.24 in33.62 cm
- Area311.5 in²2,009.68 cm²
- Aspect ratio16:9
Formula and assumptions
For a diagonal D and an aspect ratio A : B
scaleequalsD ÷ √(A² + B²)
widthequalsA × scale
heightequalsB × scale
areaequalswidth × height
1 inch = 25.4 mm exactly
Assumptions
- Screen size means the diagonal of the active rectangular display area described by the aspect ratio you entered.
- Bezels, chassis, stands, curvature and manufacturer housing are not estimated.
- Curved screens are treated as flat: the figures describe the panel measured flat.
- Pixel density is only calculated when you supply a resolution.
Questions
Why do two screens with the same diagonal have different widths?
A diagonal alone does not describe a shape. A 34-inch 21:9 screen is much wider and shorter than a 34-inch 16:9 screen, because the same diagonal is distributed differently between width and height.
Does this include the bezel or the stand?
No. Screen size refers to the diagonal of the active display area. Bezels, chassis, stands and curvature vary by model and are not estimated here.
Is the drawing shown at real size?
No. The rectangle is drawn to the correct proportion, but browsers cannot know the physical size or density of your display, so nothing on screen is calibrated to real-world dimensions.
Why is a 27-inch screen not 27 inches wide?
The 27 inches is measured corner to corner. For a 16:9 screen that works out at roughly 23.5 inches wide and 13.2 inches tall.