Display details
Measure the visible panel, not the outer bezel.
Free display dimensions calculator
Screen Size Calculator
A screen size calculator converts a display's diagonal and aspect ratio into its exact physical width, height, and visible area. Compare TVs, monitors, laptops, and phones in inches and centimeters instantly.
Calculated size
16:9 display
55.0"
Width
47.94 in
121.76 cm
Height
26.96 in
68.49 cm
Diagonal
55.00 in
139.70 cm
Screen area
1,292.6 in²
8,339.2 cm²
Fit check: allow extra room for the bezel, stand, cables, and ventilation. These results cover the visible panel only.
How the calculation works
The diagonal is the hypotenuse of a right triangle. The aspect ratio provides the relative width and height.
1. Enter diagonal
Use the advertised screen size in inches or centimeters.
2. Set ratio
Choose 16:9, 21:9, 16:10, 4:3, or a custom ratio.
3. Compare dimensions
Use physical width, height, and area to plan a real-world fit.
width = diagonal × ratio width ÷ √(ratio width² + ratio height²)
Screen size questions
How is screen size measured?
Screen size is the diagonal distance between opposite corners of the visible display, excluding the bezel. Two displays with the same diagonal can have different widths and heights when their aspect ratios differ.
How wide is a 55-inch TV?
A 55-inch TV with a 16:9 screen is about 47.94 inches wide and 26.96 inches tall before adding its bezel or stand. The complete television will be slightly larger, so check the manufacturer's exterior dimensions before installation.
Does aspect ratio change the diagonal screen size?
No. The diagonal stays the same, but aspect ratio changes how that diagonal is divided into width and height. A 21:9 display is wider and shorter than a 16:9 display with the same diagonal.
Does this calculator include the bezel or stand?
No. Results describe the visible rectangular screen only. Add the manufacturer's bezel, chassis, and stand dimensions when checking whether a TV or monitor fits a desk, wall, cabinet, or mount.
What aspect ratio should I use?
Use 16:9 for most TVs and monitors, 21:9 for common ultrawide monitors, 16:10 for many laptops and productivity displays, 4:3 for older screens, or the exact ratio listed by the manufacturer.
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