Screen Size Calculator - Calculate Width, Height & Area
Calculate screen width, height, and area from diagonal size and aspect ratio. Free online screen size calculator.
How is Screen Size Calculated?
Screen size is measured diagonally from one corner to the opposite corner. To find the actual width and height, we use the aspect ratio — the proportional relationship between width and height. Given the diagonal (d) and aspect ratio (w:h), the width is d × w / √(w² + h²) and the height is d × h / √(w² + h²).
Example
A 27-inch monitor with a 16:9 aspect ratio has a width of approximately 23.53 inches (59.77 cm) and a height of approximately 13.24 inches (33.62 cm). The total screen area is about 311.5 sq inches.
Common Use Cases
- Comparing monitors or TVs — knowing the physical dimensions helps determine if a screen fits your desk or wall space.
- Planning a multi-monitor setup — calculating combined width and height for side-by-side or stacked arrangements.
- Designing UI layouts — understanding the actual pixel density and physical size of your target display.
FAQs
Why is screen size measured diagonally?
Diagonal measurement is an industry standard that allows a single number to represent screen size regardless of aspect ratio. It has been the convention since CRT televisions.
Does bezel size affect the calculation?
No — this calculator uses the viewable display area only. The bezel (frame around the screen) adds to the overall physical dimensions but is not part of the diagonal measurement.
What is the most common aspect ratio?
16:9 is the most common for modern monitors and TVs. 16:10 is popular for productivity monitors, and 21:9 (ultrawide) is increasingly common for immersive gaming and multitasking.